Question: Scientists find dinosaur fossils in the bottom rock layers of a cliff and mammal fossils in the middle rock layer of the cliff. Which could best be concluded from this evidence?

  Options: 
 A. Dinosaurs ate plants.
 B. Dinosaurs were eaten by the mammals.
 C. Dinosaurs lived on Earth before the mammals.
 D. Dinosaurs and mammals lived at the same time.
Answer: C