About Monopolistic Competition. a. Why do monopolistically competitive firms advertise? b. If all firms are selling an identical good, can the market be monopolistically competitive? What might be the source of their market power? Briefly explain your answer. c. If a typical firm in a monopolistically competitive market is operating at full capacity, can the market be in long-run equilibrium? Briefly explain your answer. What would we expect to happen to the number of firms in this market and why