If a Single-Price Monopolist's Price Equals Marginal Cost,the Firm

If a single-price monopolist's price equals marginal cost,the firm

A) could increase its profits by lowering output and raising price.
B) should maintain its current price because it is a price taker.
C) will find it more profitable to produce a greater output.
D) is producing where MR = MC and thus is maximizing profits.
E) should definitely shut down.