In a Two-Nation, Two-Good World, If Country a Has the Comparative

In a two-nation, two-good world, if country A has the comparative advantage in producing good X over country B, then country A:

A) Should not trade with country B
B) Could have the comparative advantage in producing the other good Y as well
C) Must have the comparative disadvantage in producing the other good Y
D) Can produce good X with fewer resources than country B