dew evaporating on the rock leaves decaying on the rock snow melting in a crack in the rock water freezing in a crack in the rock
I gave my students this multiple choice question: Which of the following is most likely to make a rock crack and crumble?

Only one answer is correct among these 4 choices:
- dew evaporating on the rock
- leaves decaying on the rock
- snow melting in a crack in the rock
- water freezing in a crack in the rock

Could you tell me which one is correct?

water freezing in a crack in the rock