Given below are two statements, one labelled as Assertion (A) and the other as Reason (R). In the light of the above statements, choose the correct answer from the options given below.
Assertion (A):Carbon monoxide (CO) has a direct greenhouse effect.
Reason (R):Carbon monoxide in the atmosphere can form carbon dioxide (CO2) and can also affect the concentration of methane (CH4).
ABoth A and R are correct and R is the correct explanation of A
BBoth A and R are correct but R is not the correct explanation of A
CA is correct but R is not correct
DA is not correct but R is correct ✓ Correct
Correct answer: (D) A is not correct but R is correct
Explanation
Carbon monoxide does not act as a direct greenhouse gas, so the assertion is wrong.
It absorbs little infrared radiation itself and warms the climate only indirectly.
The reason is correct because carbon monoxide oxidises into carbon dioxide in the air.
It also consumes hydroxyl radicals, letting methane concentrations rise.
The assertion fails while the reason gives an accurate indirect mechanism.
Through these pathways carbon monoxide is counted as an indirect greenhouse gas.
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