# The equilibrium constant for the reaction $N_2(g) +O_2(g) \leftrightharpoons 2NO(g)$ at temperature $T$ is $4 \times 10^{-4}$. The value of $Kc$ for the reaction $NO(g) \leftrightharpoons \frac{1}{2} N_2 (g) + \frac{1}{2} O_2 (g)$ at the same temperature is
( A ) $4 \times 10^{-4}$
( B ) $50$
( C ) $0.02$
( D ) $2.5 \times 10^2$