FIGURE 13- 3 the Demand and Supply Curves Shown Below

FIGURE 13- 3 The demand and supply curves shown below apply to a competitive market for a factor used in the production of widgets.

-Refer to Figure 13- 3.This factor market is in equilibrium at point B.Which of the following statements best describes factor payments at point B?

A) total factor earnings are $320 and the 40th unit earns zero rent
B) total factor earnings are $320
C) economic rent to the 40th unit is $320
D) total income paid to the factor is $8
E) total factor earnings are $320 and the 40th unit earns economic rent of $8