active migration of sand dunes polished appearance of rock surfaces marine fossils found in mountains bones of animals found on the ground
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Which of these provides the best evidence that the environment of Earth has changed over millions of years?
Possibilities:
- active migration of sand dunes
- polished appearance of rock surfaces
- marine fossils found in mountains
- bones of animals found on the ground

marine fossils found in mountains