Correct option is (d) 1, 2 and 3
Excessive burning of coal, wood, kerosene, petrol etc. release toxic gases such as SO2 (sulphur dioxide), NOx (oxide of nitrogen), CO (carbon monoxide) and hydrocarbons in the air. These gases are also emitted by industries, power plants, automobiles and aircrafts. Says So, statement 2 is correct.
Coal ash contains contaminants like mercury, cadmium and arsenic. So, statement 1 is correct.