SO2 as pollutant can be controlled by(I) using solar energy, nuclear energy, hydroelectric energy.(II) low sulphur fuels, natural gas.(III) desulphonation of high-sulphur coal and oil before burning by FGD.(IV) using water under high pressure.Correct methods are

SO2 in the atmosphere is due to burning of sulphur containingfossil fuel, S+O2  →   SO2   andfrom smelting and roasting of sulphides.CuFeS2+O2  →   Cu2O + FeO +SO2  SO2 content can be controlled by using alternate source of energy for burning, as nuclear energy, solar energy, hydroelectric energy.Fuels containing sulphur are desulphonated before burning by FGD (Fuel Gas Desulphurisation).If H2O under high pressure is used, it will dissolve SO2 and will make acid rain.H2O +SO2 →   H2SO3It will lower pH of the soil and thus fertility is decreased.