Which of the following best describes the problem faced by a monopoly seller selling a durable good: Select one: O a. Renting out the durable good weakens the seller's market power versus selling at a single price each period O b. Durability makes it harder for the seller to price discriminate between buyers buying in different time periods O c. The seller faces competition from future versions of itself who have incentive to sell output beyond the profit maximizing quantity at lower prices In a perfectly competitive market of identical firms, in long run equilibrium each firm: Select one: O a. Maximizes its profit O b. All options are correct O c. Earns zero profit O d. Produces at efficient scaleWhich of the following best describes the short run supply curve of a firm in a perfectly competitive market? Select one: O a. The firm's marginal cost curve above its average variable cost O b. The firm's marginal revenue line O c. The firm's marginal cost curve above its average cost O d. The market price line Which of the following is NOT an example of price discrimination? Select one: O' a. Bundling two goods together O b. Multi-market monopoly O c. Multi-plant monopoly O d. Quantity discounts