When the wage rate falls to $15,the marginal product of capital rises,encouraging the firm to rent more machinery and hire more labor. As a result,the MRPL curve shifts from MRPLI to MRPL2, generating a new point C on the firm's demand for labor curve. Thus A and C are on the demand for labor curve,but B is not. When the wage rate falls to $15, the marginal product of capital rises, encouraging the firm to rent more machinery and hire more labor. ` As a result, the MRPL curve shifts from MRPL1 to MRPL2 , generating a new point C on the firm's demand for labor curve. Thus A and C are on the demand for labor curve, but B is not