When Comparing a Perfectly Competitive Firm and a (Single- Price)

When comparing a perfectly competitive firm and a (single- price) monopolist, a major difference is that

A) the perfect competitor achieves productive efficiency, but the monopolist does not.
B) the monopolist produces where MR = MC, but the perfect competitor does not.
C) the monopolist achieves allocative efficiency but the perfect competitor does not.
D) the perfect competitor minimizes its costs, but the monopolist does not.
E) the perfect competitor produces where P = MC, but the monopolist does not.