Figure 18-1

Figure 18-1.On the graph,L represents the quantity of labor and Q represents the quantity of output per week.
-Refer to Figure 18-1.Suppose the firm sells its output for $15 per unit,and it pays each of its workers $750 per week.When output increases from 210 units to 285 units,

A) the marginal cost is $10 per unit of output.
B) the marginal revenue is $5 per unit of output.
C) the value of the marginal product of labor is $4,275
D) the firm's profit decreases.