A Monopolistically Competitive Market Is Like Both a Competitive Market

A monopolistically competitive market is like both a competitive market and a monopoly in that

A) all three market structures feature easy entry by new firms in the long run.
B) firms in all three market structures maximize profit by producing an output level where marginal revenue equals marginal cost.
C) firms in all three market structures produce the welfare-maximizing level of output.
D) All of the above are correct.