Answer questions (19) - (21) based on the following diagram: Good Y (Car) specialization 200 150 b Trade price line Slope = -1 PPF ".......... Slope= -2 100 200 Good X (Cheese) This diagram indicates a hypothetical country's production possibility frontier and the world trade equilibrium price of Cheese (or Car). Suppose that this country specializes in car production (good Y) , as indicated above, under free trade. 19. To this country, the opportunity cost of exporting 50 cars is equal to: A) 10 units of cheese B) 15 units of cheese C) 20 units of cheese 25 units of cheese