The correct answer is option (a) i.e. the equilibrium constant is 0.0167
We know,
The equilibrium constant is kc = Concentration of product/ concentartion of reactants,
kc = [C][D] / [A][B],
Now,
kc= [4.00]*[4.0] / ( [9.60] * [10.00] ) = 0.166 ≈ 0.167
Thus, the equilibrium constant is 0.0167