Nitrous oxide is:
1.Also known as laughing gas
2.Colorless & non-flammable gas
3.One of the pollutants to measure National Air Quality Index
4.One of the greenhouse gases covered in Kyoto Protocol
Select the correct option from codes given below:
A1, 2 & 3
B2, 3 & 4
C1, 2 & 4
D1, 3 & 4