N molecules of an ideal gas at temperature $T_1$ & pressure $P_1$ are contained in a closed box.If the molecules in the box get doubled,keeping total K.E same then if new pressure is $P_2$ & temperature is $T_2$ then

Question

$\begin{array}{1 1}(A)\;P_2=P_1,T_2=T_1\\(B)\;P_2=P_1,T_2=\large\frac{T_1}{2}\\(C)\;P_2=2P_1,T_2=T_1\\(D)\;P_2=2P_1,T_2=\large\frac{T_1}{2}\end{array} $