Which of the following statements are correct ?
(i) Benzene hexachloride (BHC) is a non-biodegradable pollutant.
(ii) Anthropogenic air pollutants are natural in origin.
(iii) Carbon monoxide is a primary air pollutant.
(iv) Sulphur dioxide causes brown air effect during traffic congestion in cities.
A. 1 and 2 only
B. 1 and 3 only
C. 2 and 3 only
D. 2 and 4 only
