A
Below is a question with multiple-choice answers. Choose the correct option based on your reasoning.

### Question:
Corals are animals that live in tropical oceans. Fossils of corals are found in Ohio. What does the presence of coral fossils suggest about how the environment of Ohio has changed over time?

### Choices:
A. Ohio was once covered by warm seas.
B. A large glacier once passed over Ohio.
C. The average rainfall in Ohio is now much more than it once was.
D. The average temperature in Ohio is now much warmer than it.

### Answer:
