A) firms make zero profits.
B) firms make positive profits.
C) the industry is in long-run equilibrium.
D) the marginal benefits of consuming an extra unit of the good exactly equals the marginal cost to society of producing the good.
B) firms make positive profits.
C) the industry is in long-run equilibrium.
D) the marginal benefits of consuming an extra unit of the good exactly equals the marginal cost to society of producing the good.
ANSWER:
D