Figure 9-4 A graph of price, P, versus quantity, Q, shows a supply curve, Domestic Supply, rising linearly, and a demand curve, Domestic Demand, descending linearly. The curves intersect at P subscript 1. A horizontal line, World Price, extends from P subscript 0. Area A lies below the demand curve and above the World Price line. Area B lies to the upper left of the point of intersection, below the world price line and the demand curve. Area C lies below Area B and above the supply curve. Area D lies below the World Price line and above the equilibrium price. Refer to Figure 9-4. The change in total surplus in this market because of trade is a. D, and this area represents a loss of total surplus because of trade. b. D, and this area represents a gain in total surplus because of trade. c. B + D, and this area represents a gain in total surplus because of trade. d. B + D, and this area represents a loss of total surplus because of trade