When a country has a comparative advantage in the production of a good, it means that it can produce this good at a lower opportunity cost than its trading partner. Then the country will specialize in the production of this good and trade it for other goods. The following graphs show the production possibilities frontiers (PPFs) for Glacier and Denali. Both countries produce peas and pistachios, each initially (i.e., before specialization and trade) producing 36 million pounds of peas and 18 million pounds of pistachios, as indicated by the grey stars marked with the letter A