The Demand and Supply Curves Shown Below Apply to a Competitive

The demand and supply curves shown below apply to a competitive market for a factor used in the production of widgets. FIGURE 13-2
-Refer to Figure 13-2.If the supply and demand curves for the factor are as shown in the diagram,but the wage being paid is $9,and the market is at point C,

A) the wage is higher than the factor's marginal revenue product,and firms will reduce the amount of the factor employed.
B) the wage is higher than the factor's marginal product,and firms will reduce the amount of the factor employed.
C) the marginal revenue product is not equal to the marginal cost of the factor and firms will increase the amount of the factor employed.
D) the demand curve will shift to the right until equilibrium factor price and quantity are re-established.
E) the demand curve will shift to the left until equilibrium factor price and quantity are re-established.