It is believed that areas that are now covered by water used to be dry land. What sentence from the selection best explains why?
A. Old tree stumps have been found in deep water.
B. The types of animals that lived on the earth then were also different.
C. People were exploring the mountains of Europe.
D. It was hard for life to exist in such deep cold.
The best answer is A. Old tree stumps have been found in deep water.
Explanation: This sentence directly indicates that there were once trees (and therefore dry land) in areas that are currently underwater, supporting the belief that these regions were once dry land. The discovery of old tree stumps suggests that living organisms existed in that area when it was above sea level.