Which of the Following Statements Is TRUE

Which of the following statements is TRUE?

A) If the monopolist's marginal revenue is greater than its marginal cost, the monopolist can increase profit by selling more units at a lower price per unit.
B) If the monopolist's marginal revenue is greater than its marginal cost, the monopolist can increase profit by selling fewer units at a higher price per unit.
C) When a monopolist produces where MR = MC it always earns a positive economic profit
D) A monopolist is guaranteed monopoly profits.