2. Scientists are confused by the different ways the rocks move, and theories involving wind, ice, and mud have not been confirmed.
Explanation:
The sentence that best identifies the main idea of paragraph two is the second option because it is talking about the different ways rocks move and the possible explanations that scientists have, but that are yet to be confirmed. The sentence shows the confusion of the scientist towards the phenomenon and how they are still trying to explain it.
the other options are incomplete or do not represent how the scientist feel about the way these rocks move.
