Given the graph, a profit-maximizing firm in a perfectly competitive industry would charge a price of: A graph titled Profit-Maximizing Monopolist shows a demand curve and an MR curve. The horizontal axis represents Quantity, and the vertical axis represents Price, cost, marginal revenue. The demand curve and the MR curve start at a common point on Price and have negative slopes. A horizontal line, labeled MC equals ATC, starts at 20 on price and runs parallel to quantity. The line intersects the MR curve at 1,000 on quantity and the demand curve at 2,000 on quantity. The area below the demand curve bounded by 40 dollars on price is labeled as A. The area below 40 dollars and bounded by the MC equals ATC line and 1,000 on quantity is labeled as B. The area below the MC equals ATC line bounded by 1,000 on quantity is labeled as C. The area between 40 and 20 dollars on price and 1,000 and 2,000 on quantity, below the demand curve, and bounded by MC equals ATC line is labeled as D. zero. $20. $40. between $20 and $40