An enclosure of volume `3` litre contains `16g` of oxygen, `7 g` of nitrogen and `11 g` of carbon - di-oxide at `27^(@)C`. The pressure exerted by the mixture is approximately
`[R = 0.0821 lit "atm mole"^(-1) K^(-1)]`
A. `1` atmosphere
B. `3` atmosphere
C. `9` atmosphere
D. `8.3` atmosphere