If the Country of Zebland Has a Comparative Advantage in the Production

If the country of Zebland has a comparative advantage in the production of wheat over the country of Bluesky, then:

A) in Zebland, the opportunity cost of producing wheat is higher than in Bluesky.
B) in Zebland, the opportunity cost of producing wheat is lower than it is in Bluesky.
C) neither Bluesky nor Zebland should specialize only in the production of wheat.
D) Zebland will export all of its wheat.