Which one of the following pairs of gases are the major cause of...

The phenomenon of keeping the earth warm due to presence of certain radiatively gases in the atmosphere is called green house effect (Fourier, 1827). The name is based after a similar warmer interior in a glass-enclosed green house where glass panes, $\mathrm{CO}_2$ and water vapour allow the solar radiations to enter but prevent the escape of long wave heat radiations. $\mathrm{CO}_2$ and $\mathrm{N}_2 \mathrm{O}$ are the major cause of "green house effect". $\mathrm{CO}_2$ contributes $60 \%$ of total global warming. $\mathrm{N}_2 \mathrm{O}$ contributes $6 \%$ to green house effect.