Repeated expansion and contraction of rocks due to temperature range is an example of what?

Correct answer: Physical weathering

Direct answer: Option A, physical weathering. A temperature range means repeated heating and cooling. On heating, rock minerals expand; on cooling, they contract. Different minerals may expand by different amounts, and the outer surface may heat and cool faster than the interior. Repetition creates mechanical stress, cracks, and eventually the breaking or peeling of rock without requiring a chemical change. Option A is correct because this is mechanical disintegration. Option B is wrong because carbonation is chemical weathering involving carbonic acid, usually formed when carbon dioxide dissolves in water. Option C is wrong because hydrolysis is a chemical reaction between minerals and water. Option D is wrong because organic acid action involves acids produced by organisms or decaying matter and is chemical. Hot, dry areas often show strong thermal stress because daily temperature differences can be large, but the classification depends on the mechanical action. Memory cue: temperature changes break; they do not chemically transform—physical weathering.