The correct answer is: "A country makes the goods it produces most efficiently and trades for others".
Countries or companies specialize on producing goods or services where they have acquired a competitive advantage.
A comparative advantage is defined as the superiority that a producer enjoys and which enables him to manufacture a certain product at a lower cost, or with a higher quality, if compared to its competitors. Therefore, this country becomes the most efficient producer which is able to elaborate the product with the lowest opportunity cost.
