A source is something that is used to learn information on a topic. In this case, David needs something that will help him learn about different endangered animals.

Of our answer choices, the best answer is an article that discusses various endangered animals. A chart the includes pictures of endangered animals wouldn't provide enough information to write a report. Also, the report is on more than just one endangered animal; thus, information only on the Bald Eagle would not be as helpful as an article that discusses several endangered animals.

A source is something that is used to learn information on a topic. In this case, Alison needs something that will help her learn about all of the planets so that she can write a report on it. Of our answer choices, the best answer is a book that discusses each planet.

A book that provides details about just one planet won't be very helpful to Alison because she is writing a report on all of the planets in the solar system. Also, a chart that only outlines each planet's rotation around the sun won't provide Alison with enough information to right a report on each planet.