Suppose Shirley's Shoe Company is the only producer of shoes in the market and is, therefore, a monopolist. The market demand curve and the company's marginal revenue (MR) and marginal cost (MC) functions are: Demand: P = 360 - 4Q MR = 360 - 8Q MC = 4Q If this company charges a single price to all consumers of shoes, its profit-maximizing output level (QM) and price (PM) are: O QM = 30, PM = 120 O QM = 30, PM = 180 O QM = 30, PM = 240 O QM = 45, PM = 180 O QM = 90, PM = 0