You are presented with the question "Cycles of freezing and thawing water cause " and the following answer choices: 
- exposure to cold
 - the oak can fall
 - mechanical weathering
 - the looseness of soil
 - In the winter
 - Metling snow
 - colder and wetter
 - looseness of dirt or compost

Now knowing that cycles of freezing and thawing water cause ice wedging and ice wedging is the most important form of mechanical weathering, choose the best answer.


 

   mechanical weathering      