Consider the Equilibrium,Cl₂(g)+ 2 NO(g) $\leftrightarrows$ 2 NOCl(g)When 2 $\times$ 10^-4

Consider the equilibrium,Cl₂(g) + 2 NO(g) $\leftrightarrows$ 2 NOCl(g) .When 2.000 M NOCl is placed in a tank at 500.0 K and allowed to come to equilibrium,the equilibrium concentration of Cl₂ is 0.979 M.Calculate K_c.

A) 45.6
B) 15.2
C) 0.938
D) 2130
E) 4.70 $\times$ 10^-4