Whats the answer?

Choose the statement about monopolistic competition that is correct. O A. The firm's markup results from the firm producing the quantity at which marginal cost does not equal marginal revenue. O B. Monopolistic competition can never be considered to be efficient. O C. The efficient degree of product variety is the one for which the marginal social benefit of product variety equals its marginal social cost. O D. The firm can incur an economic loss or make an economic profit in the short run but in the long run the firm makes an economic profit or breaks even