Which of the following is a step taken by the government of India to control air pollution?
1
Mandatory mixing of 20% ethyl alcohol with petrol and 20% biodiesel
2
Compulsory PUC (Pollution Under Control) certification of petrol driven vehicles, which tests for carbon monoxide and hydrocarbons
3
Use of non-polluting Compressed Natural Gas (CNG) only as fuel by all buses and trucks
4
Both 1 and 3