18. Producer surplus is: a. Represented by the area below the demand curve and above the "price line,\" and to the left of equilibrium quantity. b. Represented by the area below the "price line'l and above the industry supply curve, and to the left of equilibrium quantity. c. Represented by the area below the "price line" and above the industry supply curve, and to the right of equilibrium quantity. d. The area that is both above the supply curve and below the demand curve. e. The same as the economic surplus