NO₂ and SO₂ after reacting with water in atmosphere produce HNO₃ & H₂SO₄ which falls down as acid rain.

Correct Option: A

NO₂ and SO₂ after reacting with water in atmosphere produce HNO₃ & H₂SO₄ which falls down as acid rain.

CO₂ in its normal fraction in air (about 0.03%) is actually not a pollutant but above this it is considered as a pollutant. At the elevated level it becomes a cause for global warming.

Correct Option: B

CO₂ in its normal fraction in air (about 0.03%) is actually not a pollutant but above this it is considered as a pollutant. At the elevated level it becomes a cause for global warming.

Lead (Pb) is the most hazardous metal pollutant present in automobile exhaust.

Correct Option: C

Lead (Pb) is the most hazardous metal pollutant present in automobile exhaust.

Above 80 dB sound becomes hazardous.

Correct Option: B

Above 80 dB sound becomes hazardous.

Automobile exhaust is the main cause of air pollution in metro cities.

Correct Option: A

Automobile exhaust is the main cause of air pollution in metro cities.