Question

what is a process by which carbon is very slowly returned to the atmosphere from rocks being worn by long exposure to things like rain and freezing and thawing cycles?
weathering
fossilization
combustion

Explanation:

Weathering breaks down rocks via rain, freeze-thaw cycles, and other environmental forces, slowly releasing stored carbon back into the atmosphere. Fossilization locks carbon into organic matter/rocks, and combustion is a rapid carbon release process from burning fuels.

Answer:

weathering