Fact 1: Ice wedging is when ice causes rocks to crack by expanding in openings.

Fact 2: Ice wedging is the most important form of mechanical weathering.

Given the two facts above, answer the question "What does mechanical weathering do to a rock?" with the following options: 
- move to different locations
 - Causes it to crack
 - Makes it shrink
 - break off
 - Regrows it
 - decreases its bodily water
 - Moves it
 - Causes it to grow


 

  Causes it to crack       