Answer:
The correct answer is option a. "ice forming in cracks of rocks".
Explanation:
Physical weathering is a geological process that results in rocks breaking apart, but with a physical force that does not change its composition. Ice forming in cracks of rocks is an example of physical weathering known as Ice wedging. It results from water seeping down into the cracks of rocks, and when the temperature drops and water freezes, the water cracks the rocks as it expands when it becomes ice.
