Ignoring oligopoly and focusing on the other three types of market structure, in which of those market structures does a profit maximizing firm charge a price that exceeds marginal cost? A. monopoly only b. monopoly and monopolistic competition only c. monopoly, monopolistic competition, and perfect competition d. It depends on whether we are in the short run or the long run. . Ignoring oligopoly and focusing on the other three types of market structure, in which of those market structures does a profit maximizing firm experience a zero economic profit? A. perfect competition only b. perfect competition and monopolistic competition only c. perfect competition, monopolistic competition, and monopoly d. It depends on whether we are in the short run or the long run.