Final answer:
The true statement about a two-nation, two-good world is that if one nation holds a comparative advantage in one product, the other nation will have a comparative advantage in the other product. This is because nations benefit by specializing in goods where they have a lower opportunity cost, which defines their comparative advantage.
Step-by-step explanation:
In a two-nation, two-good world, the statement that is true is: b) If one nation has the comparative advantage in one product, then the other nation would have the comparative advantage in the other product.
Absolute advantage refers to the ability of a country to produce a good using fewer resources compared to another country. However, comparative advantage involves producing a good at a lower opportunity cost than other countries. Comparative advantage is what determines the basis for trade, as it benefits countries to specialize in goods where they have a comparative advantage and trade for other goods.
Even when a nation has an absolute advantage in both products, it will benefit by specializing in the product it produces with the least opportunity cost, thus having comparative advantage, while the other nation will have the comparative advantage in the product that it gives up less to produce.