Consider the following reaction at equilibrium. What effect will adding some C have on the system? CO2(g) + C(graphite) = 2 CO(g) Answer A. No effect will be observed since C is not included in the equilibrium expression. B. The equilibrium constant will decrease. C. The reaction will shift to the left in the direction of reactants. D. The equilibrium constant will increase. E. The reaction will shift to the right in the direction of products.