Peeling of rock in shell-like layers is linked with which process?

Correct answer: Exfoliation

The direct answer is B, exfoliation. Exfoliation is a type of physical weathering in which outer rock layers peel away in curved or shell-like sheets. Step by step: the rock surface is repeatedly heated and cooled, or pressure is released when overlying material is removed; the outer part expands and contracts, or expands because of pressure release; parallel cracks develop near the surface; thin outer layers separate and peel off. Option B is correct because shell-like peeling is the defining visual clue for exfoliation. Option A, carbonation, is a chemical process in which carbonic acid helps dissolve carbonate rocks, especially limestone; it does not specifically mean peeling sheets. Option C, oxidation, involves reaction with oxygen, commonly producing rust-like colours in iron-bearing minerals. Option D, hydration, involves minerals taking in water and expanding or changing chemically; it is not the name for curved layer peeling. Heating and pressure release are common causes, although exfoliation can have more than one mechanism. Memory cue: outer shells peeling from a rock = exfoliation.