The correct option is A SO2
Bhopal Gas Tradegy
Oxides of sulphur SO2 and nitrogen released by the burning of fossil fuels or industries in the atmosphere.
These oxides react with water or other molecules to form sulphuric acid and nitric acid respectively. These acids, after being dissolved in the rain water, make it acidic. This is called acid rain.
These acids have the ability to corrode the surfaces of monuments over a prolonged duration.
Final answer
(a) SO2