A. Without trade, the price of a pair of white socks (in terms of red socks) in Boston is_of red socks, and in Chicago it is_of red socks. B. _ has an absolute advantage in the production of red socks, and_has an absolute advantage in the production of white socks._has a comparative advantage in the production of red socks, and_has a comparative advantage in the production of white socks.
C. If the cities trade with each other, Boston will export_socks, and Chicago will export_socks.
D. The price of white socks can be expressed in terms of red socks. The highest price at which white socks can be traded that would make both cities better off is_of red socks per pair of white socks, and the lowest price that makes both cities better off is_of red socks per pair of white socks.