You are presented with the question "What do cycles of freezing and thawing water cause?" and the following answer choices: 
- Metling snow
 - Mechanical weathering
 - the looseness of soil
 - fissures of hot, acidic water
 - exposure to cold
 - Plant growth is reduced
 - heat production
 - 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       