Graphically, the marginal cost curve is a. a u shape, initially falling when the marginal product of labor is rising and then eventually rising when the marginal product of labor is falling. b. shaped like a hill, rising when the average cost of production is rising and then eventually falling when the average cost of production is falling. c. shaped like a hill, initially rising when the marginal product of labor is falling and then eventually falling when the marginal product of labor is rising. d. a u shape, initially falling when the marginal product of labor is below marginal cost and then eventually rising when the marginal product of labor is above marginal cost. e. a u shape, initially falling due to diminishing returns and then eventually rising due to division of labordivision of labor.