He diagram below represents a stack of rock layers. Examine the diagram, and answer the question that follows. What do these layers and their fossils suggest about Earth's history?
A.
Lifeforms on Earth have been the same over time.
B.
No lifeforms were present when these layers formed.
C.
There have been changes in Earth's lifeforms over time.
D.
Only one kind of lifeform lived where these layers formed.