These mountains were once under the ocean. These mountains once had a more rainy climate. Mountain river clams evolved from ocean clams. Ocean clams evolved from mountain river clams.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Imprints of the shells of ocean clams are often found in the rocks of the Appalachian Mountains. What do these imprint fossils most likely indicate?
Possibilities:
- These mountains were once under the ocean.
- These mountains once had a more rainy climate.
- Mountain river clams evolved from ocean clams.
- Ocean clams evolved from mountain river clams.

These mountains were once under the ocean.