Both are forces. Both affect weather. Both form new kinds of rock. Both are forms of weathering.
I gave my students this multiple choice question: Tree roots can grow into rock and break it apart. Water can freeze in the cracks of rock, causing it to break apart. How are these two processes alike?

Only one answer is correct among these 4 choices:
- Both are forces.
- Both affect weather.
- Both form new kinds of rock.
- Both are forms of weathering.

Could you tell me which one is correct?

Both are forms of weathering.