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.