28gm of $N_2$ gas is contained in a flask at a pressure 10atm and at a temperature of $57^{\large\circ}$C.It is found that due to leakage in the flask,the pressure is reduced to half & temperature is reduced to $27^{\large\circ}$C.Quantity of $N_2$ leaked out

Question

$\begin{array}{1 1}(A)\;11/20gm\\(B)\;80/11gm\\(C)\;5/63gm\\(D)\;63/5gm\end{array}$