Concept:Heating and cooling of rocks is a physical weathering process that breaks rocks into smaller pieces.
Explanation:During the day, the sun heats the rock surface, causing the outer layers to expand.
At night, the rock cools quickly, causing the outer layers to contract.
The inner part of the rock changes temperature more slowly than the outer surface.
This constant expansion and contraction creates stress inside the rock.
Over time, cracks develop along the surface and grain boundaries.
Repeated cycles of alternate heating and cooling weaken the rock.
Eventually, the rock breaks apart into smaller fragments.
This process is one form of physical or mechanical weathering.
Answer:The correct answer is D. fragmentation.