erosion. deposition. physical weathering. chemical weathering.
I gave my students this multiple choice question: Today's limestone caverns were once solid rock. Acidic rainwater seeping through the rock over hundreds of years dissolved part of the rock, forming caverns. This is an example of

Only one answer is correct among these 4 choices:
- erosion.
- deposition.
- physical weathering.
- chemical weathering.

Could you tell me which one is correct?

chemical weathering.