It was once below a waterfall. It was once part of a riverbed. It was once covered by an ocean. It was once near a freshwater lake.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A researcher found shark fossils on top of a mountain. This evidence suggests which of the following about this region?
Possibilities:
- It was once below a waterfall.
- It was once part of a riverbed.
- It was once covered by an ocean.
- It was once near a freshwater lake.

It was once covered by an ocean.