Concept:Chemical weathering involves changes in the mineral composition of rocks through chemical reactions.Explanation:Carbonation is a chemical weathering process.Rainwater combines with carbon dioxide from the air to form a weak carbonic acid.The reaction is:H2O+CO2→H2CO3This weak acid reacts with rocks such as limestone, dissolving them gradually.Fragmentation, exfoliation, and shattering are physical weathering processes, not chemical ones.Answer:C. carbonation