Answer please

Why don't some firms in monopolistic competition earn losses in the long run? O A. The firms have enough monopoly power to ensure they always earn profits. O B. Free entry allows enough firms to remain in the market and maintain the critical mass of firms required to attract customers. O C. Free exit implies that any unprofitable firms leave the market in the long run. O D. In the long run, firms will build enough brand loyalty among customers to ensure a profitable level of sales