Answer: D. Somas
Explanation:
When a sedimentary rock is forming particles from existing rocks chip off their parent rocks and are eroded to a new location. These combine with minerals and fossils of plants and animals to form layers of sedimentary rocks.
In this question, the series of strata from the top of the rock (the newest) to the bottom of the rock (the oldest) are: Garret, Talos, Richmond, Pitts and Somas. Because the oldest strata is Somas, the oldest fossils will be found here.
