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

### Question:
Rich beds of marine fossils have been found in Florida. By dating these fossils, scientists can best determine

### Choices:
A. when Florida collided with the North American continent.
B. the date when organisms moved onto dry land.
C. the period during which Florida was covered in water.
D. when the atmosphere of Earth was more humid than it is today.

### Answer:
