`28 g "of" N_2` gas is contained in a flask at a pressure of `10 atm` and at a temperature of `57^@ C`. It is found that due to leakage in the flask, the pressure is reduced to half and the temperature to `27^@ C`. The quantity of `N_(2)` gas that leaked out is.
A. `11//20 g`
B. `20//11 g`
C. `5//63 g`
D. `63//5 g`