The answer is "heating and pressurization of shale."

Metamorphic rocks are any rock type that has been altered by heat, pressure, and/or the chemical action of fluids and gases. Metamorphic rocks are classified by their structure and their dominant minerals. Metamorphic rock structure is either foliated (has a definite planar structure) or nonfoliated (massive, without structure). Metamorphic rocks include slate, phyllite, schist, and gneiss.

Sedimentary rocks are layered rocks that are composed of accumulated sediments. Erosion and deposition play a key part in the formation of sedimentary rocks. Wind, water, ice, and chemicals break down existing rock into sediment that is then transported and deposited by wind, water, and glaciers.

As sediment accumulates with time (thousands of years) it becomes compacted and cemented (lithified), eventually forming rock. Some common sedimentary rocks are shale, sandstone, limestone, and conglomerate.

Igneous rocks are those that solidify from a molten or partially molten state. These rocks are characterized as either extrusive or intrusive. Extrusive rocks are formed above Earth’s surface as lava. Intrusive rocks form from molten material (magma) that flows and solidifies underground.

The answer is "coal takes hundreds of millions of years to form." None of the other answer choices are true. 

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production.

Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity.

Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir.

Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production.

Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity.

Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir.

Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

The answer is "prehistoric algae and zooplankton whose remains settled on the bottom of an ocean or lake."

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production.

Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity.

Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir.

Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production.

Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity.

Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir.

Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

The answer is "all of these." Fracking can cause pollution of surface and groundwater, sedimentation of streams from construction of roads and well pads, dewatering of streams, and displacement of wildlife.

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production.

Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity.

Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir.

Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production. Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity. Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir. Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production. Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity. Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir. Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

The answer is "in oceans, on land." Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production. Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity. Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir. Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.

The answer is "sedimentary rock containing remains of dead organisms from millions of years ago."

Fossil fuel is a general term for crude oil, coal, natural gas, or heavy oils. These fuels were initially large deposits of organic material that were transformed into combustible materials. This happened because of exposure to heat and pressure in the earth's crust over hundreds of millions of years. Fossil fuels are a nonrenewable resource, but they make up the majority of our energy production. Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly (for heating and industrial processes) or to fuel power plants for electricity. Extracting crude oil normally starts with drilling wells into an underground reservoir. When an oil well has been tapped, a geologist will note its presence. Often many wells (called multilateral wells) are drilled into the same reservoir. Natural gas is most commonly extracted by drilling vertically from the Earth's surface. Hydraulic fracturing, horizontal drilling, and acidizing are processes to expand the amount of gas that a well can access.