The Equilibrium Constant,K_p,has a Value of 6 $\times$ 10^-4 at 308 K for the Reaction of Nitrogen Monoxide

The equilibrium constant,K_p,has a value of 6.5 $\times$ 10^-4 at 308 K for the reaction of nitrogen monoxide with chlorine.
2NO(g) + Cl₂(g)
2NOCl(g)
What is the value of K_c?

A) 2.5 $\times$ 10^-7
B) 6.5 $\times$ 10^-4
C) 1.6 $\times$ 10^-2
D) 1.7
E) None of these choices is correct.