Which of the Following Statements Is Correct

Which of the following statements is correct?

A) Purely competitive firms, monopolistically competitive firms, and pure monopolies all earn zero economic profits in the long run.
B) Purely competitive firms, monopolistically competitive firms, and pure monopolies all earn positive economic profits in the long run.
C) In the long run, purely competitive firms and monopolistically competitive firms earn zero economic profits, while pure monopolies may or may not earn economic profits.
D) Monopolistically competitive firms earn zero economic profits in both the short run and the long run.