Which One of the Following Characteristics Is Not Shared by Single-Price

Multiple Choice

Which one of the following characteristics is not shared by single-price monopoly and monopolistic competition?

A) Firms face a downward-sloping demand curve.
B) Profit-maximizing quantity occurs where MC = MR.
C) Price charged is the highest consumers are willing to pay.
D) Firms make an economic profit in the long run.
E) The marginal revenue curve lies below the demand curve.