In a perfectly competitive market buyers want to buy 20,000 units and sellers want to sell 20,000 units of a product when the price is $50 per unit. ABC Corporation, one seller in this market: a. will sell a fixed number of units regardless of how the price changes. b. faces a downward-sloping demand curve for its product. c. faces a perfectly elastic demand curve at a price of $50. d. will maximize profit by selling at a price less than $50