Q: 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, what is a form of mechanical weathering?

Choices: [I] microbes breaking down rock [II] By coral exoskeletons [III] wind and erosion [IV] oxygen breaking down rock [V] ice expanding in rock openings [VI] removal of rock by acid rain [VII] remains of prehistoric life [VIII] fissures of hot, acidic water
The answer is:
[V]