Q: Fact 1: Cycles of freezing and thawing water cause ice wedging. Fact 2: Under the pressure of the innumerable wedges of ice, the rock cracks. Given the two facts above, what is created from cycles of freezing and thawing water?

Available choices: (I) Something that is on the Moon. (II) swamp vegetation. (III) Something that cracks rocks. (IV) sedimentary rocks. (V) A transportation fuel. (VI) fissures of hot, acidic water. (VII) Something inside the earth. (VIII) Something that flies.
The answer is:
(III)