JEE Main levelSingle correct optionDifficulty 2 of 3ev072
Match the gas in Column I with its important source in Column II.
Column I: (P) CHX4, (Q) COX2, (R) NX2O, (S) CFC-12.
Column II: (1) refrigerants and aerosol propellants, (2) nitrogenous fertilisers acted on by soil bacteria, (3) paddy fields and cattle, (4) burning of fossil fuels.
AP-3, Q-4, R-2, S-1
BP-4, Q-3, R-2, S-1
CP-3, Q-4, R-1, S-2
DP-2, Q-4, R-3, S-1
Answer: A
Methane arises from anaerobic decay in paddy fields and from cattle. Carbon dioxide mainly comes from fossil-fuel burning, nitrous oxide from bacterial transformation of fertiliser nitrogen, and CFC-12 from refrigeration and propellant use.