Suppose that in slovakia one unit of labor can produce either 20 tons of wheat or 40 tons of soy and in poland one unit of labor can produce either 40 tons of wheat or 20 tons of soy. if each country has two units of labor, which of the following consumption combinations can be attained only with trade? (assume that each unit of labor produces the same amount of output) a. slovakia consumes 80 tons of soy. b. slovakia consumes 30 tons of both soy and wheat. c. poland consumes 80 tons of wheat. d. poland consumes 40 tons of wheat and 20 tons of soy.