glaciers moving large pieces of a fractured rock tree roots growing in a fractured rock ice freezing on a rock surface wind blowing sand against a rock surface
I gave my students this multiple choice question: Which is an example of organic weathering of rocks?

Only one answer is correct among these 4 choices:
- glaciers moving large pieces of a fractured rock
- tree roots growing in a fractured rock
- ice freezing on a rock surface
- wind blowing sand against a rock surface

Could you tell me which one is correct?

tree roots growing in a fractured rock