Which of the Following Statements Is Correct

Which of the following statements is correct?

A) Firms in monopolistic competition and monopoly can earn economic profits in both the short run and the long run.
B) Both perfectly competitive and monopolistically competitive firms are price takers.
C) Both a monopolistically competitive industry and a monopoly are characterized by a very small number (or one) firm.
D) Firms can easily enter a perfectly competitive or monopolistically competitive industry.