Trade Enhances the Economic Well-Being of a Nation in the Sense

Trade enhances the economic well-being of a nation in the sense that

A) both domestic producers and domestic consumers of a good become better off with trade,regardless of whether the nation imports or exports the good in question.
B) the gains of domestic producers of a good exceed the losses of domestic consumers of a good,regardless of whether the nation imports or exports the good in question.
C) trade results in an increase in total surplus.
D) trade puts downward pressure on the prices of all goods.