If the Opportunity Cost of Producing a Ton of Coffee

If the opportunity cost of producing a ton of coffee in the U.S. is twenty tons of rice, while the opportunity cost of producing coffee in Costa Rica is two tons of rice,

A) the U.S. has a comparative advantage in rice production.
B) Costa Rica has a comparative advantage in rice production.
C) the U.S. has a comparative advantage in coffee production.
D) the U.S. would be better off not trading with Costa Rica.