Match the following correctly:
a. Carbon monoxide     1. Coal burning
b. Nitrogen oxide       2. Cigarette Smoking
c. Sulphur dioxide         3. Chemical reaction with VOCs
d. Ozone          4. Power and Industrial Plant
a b c d

Answer: [A] 2 4 1 3

This is not a very tough question. VOC can form ground-level ozone (smog) by chemical reaction, so d matches 3. Carbon monoxide(CO) is present in high levels in cigarette smoke. Rest two you can identify from the given options.

This question is a part of GKToday's Integrated IAS General Studies Module