Understanding Boldface Reasoning Practice Test

It is generally believed that an Indian tribe known as “The Red Paint People” first occupied the coast of Maine in approximately 3000 B.C. This name was given to the Indians because their graves contained quantities of a red pigment (iron ochre) that they presumably used to decorate their faces and bodies. However, recently discovered Indian grave sites on the coast of Maine that contain these same red pigments have been conclusively dated to 4000 B.C. Therefore, the “Red Paint People” must have occupied the coast of Maine much earlier than archaeologists previously believed.

In the argument above, the two portions in boldface play which of the following roles?

The latest adaptation in swimming pools is the saltwater pool. The water in such pools is 1/10 as salty as the ocean, approximating the salinity of the human body. Owners of such pools claim that the pools cause no chlorine irritation and that the salt water actually soothes and softens the skin. They also claim that such pools are less expensive to maintain than traditional freshwater pools. However, manufacturers of pool chemicals, such as chlorine, claim that the salt water system is more expensive to install and can leave behind a salt residue on some surfaces.

Which of the following best describes the roles of the boldface portions in the argument above?