Paleontologists Have Subdivided the Cenozoic Era into Epochs Because

Paleontologists have subdivided the Cenozoic era into epochs because

A) Homo sapiens evolved at the start of the Cenozoic.
B) the continents had achieved their present positions.
C) the number of species stopped increasing at this time.
D) our knowledge of the evolutionary events of the Cenozoic is more extensive than for other eras.
E) starting with the Cenozoic, the fossil record is no longer a necessary source of information about evolutionary relationships.