Fact 1: Cycles of freezing and thawing water cause ice wedging.

Fact 2: The fact is that ice seldom freezes or thaws at a uniform rate.

Given the two facts above, answer the question "What is the rate of ice wedging?" with the following options: 
- In the winter
 - erosion
 - mechanical
 - Physical weathering
 - Dilution
 - friction
 - it fluctuates
 - kinetic


 

       it fluctuates  