A firm uses 80 hours of labor and 6 units of capital to produce​ 10,000 gadgets per day.​ Labor's marginal product is 4 gadgets per hour and the marginal product of capital is 20 gadgets per unit. Each unit of labor costs​ $8 per hour and each unit of capital costs​ $50 per unit. If the firm wants to continue producing​ 10,000 gadgets per day at the lowest possible​ cost, it should A. use less of both inputs. B. use more labor and less capital. C. use more capital and less labor. D. continue using 80 hours of labor and 6 units of capital.