Which of the following pollutants are responsible for acid rain?
(i) Sulphur dioxide (SO₂) (ii) Nitrogen oxides (NOₓ) (iii) Carbon monoxide (iv) Water vapor
Select the correct answer using the codes given below:

Correct option is A

The correct answer is (A) Only (i) and (ii).
Explanation:
Acid rain is primarily caused by the emissions of sulfur dioxide (SO₂) and nitrogen oxides (NOx) into the atmosphere. 
· (i) Sulphur dioxide (SO₂): Released mainly from burning fossil fuels containing sulfur (like coal and oil) in power plants and industrial processes, SO₂ reacts with water, oxygen, and other chemicals in the atmosphere to form sulfuric acid (H₂SO₄), a major component of acid rain.
· (ii) Nitrogen oxides (NOx): Primarily released from the combustion of fossil fuels in vehicles and power plants, NOx (mainly nitrogen dioxide, NO₂) reacts with water and oxygen in the atmosphere to form nitric acid (HNO₃), another significant component of acid rain.
· (iii) Carbon monoxide: While carbon monoxide (CO) is a significant air pollutant and harmful to human health, it does not directly contribute to the formation of the strong acids (sulfuric and nitric acid) that cause acid rain.
· (iv) Water vapor: Water vapor is a natural component of the atmosphere and is essential for the  formation of acid rain, as it reacts with SO₂ and NOx to produce the acids, but it is not a  pollutant responsible for the acidity itself. 
Therefore, only sulfur dioxide and nitrogen oxides are the pollutants responsible for acid rain.