Which of the Following Governmental Actions Would Eliminate Some or All

Which of the following governmental actions would eliminate some or all of the inefficiency that results from monopoly pricing?

A) Policymakers can regulate prices that the monopoly charges.
B) Prohibit the monopoly from price discriminating.
C) Force the monopoly to operate at a point where its marginal revenue is equal to its marginal cost.
D) There is nothing the government can do to eliminate any inefficiency associated with a monopoly.