Figure 10.1 -Figure 10.1 Depicts a Firm's Marginal Revenue Product Curve. Why

Figure 10.1
-Figure 10.1 depicts a firm's marginal revenue product curve. Why does the marginal revenue product of labor decrease faster as the firm increases its use of labor by 10 hours?

A) because the marginal product of labor decreases at an increasing rate
B) because the marginal product of labor decreases at a decreasing rate
C) because the marginal product of labor increases at an increasing rate
D) because the marginal product of labor increases at a decreasing rate