UPSC Prelims 2021— Question 89

Blue carbon refers to carbon captured, stored and sequestered by coastal and marine ecosystems such as mangroves, seagrass meadows and salt marshes. Forest and agricultural soils are generally discussed as terrestrial carbon pools, petroleum and natural gas are fossil-carbon stores, and atmospheric carbon is not 'blue carbon'. The final answer-key position for Set C identifies option A as the correct option. Option A — Carbon captured by oceans and coastal ecosystems — is correct because it is the alternative that matches the constitutional, historical, geographical, scientific or economic principle established above. Option B — Carbon sequestered in forest biomass and agricultural soils — is not correct because it does not satisfy the specific condition tested in the question; it represents an alternative that is contradicted, incomplete, or less precise than the accepted answer. Option C — Carbon contained in petroleum and natural gas — is not correct because it does not satisfy the specific condition tested in the question; it represents an alternative that is contradicted, incomplete, or less precise than the accepted answer. Option D — Carbon present in atmosphere — is not correct because it does not satisfy the specific condition tested in the question; it represents an alternative that is contradicted, incomplete, or less precise than the accepted answer. For PYQ interpretation, the distinction between the correct alternative and merely related facts is important. UPSC often places plausible distractors beside the precise statement that matches the underlying rule, chronology, definition or empirical relationship. The answer should therefore be read against the exact wording of the question rather than against a broadly related fact.