Concept:Comparative advantage means producing cocoa at a lower opportunity cost than Ghana.Explanation:Nigeria has a comparative advantage if it sacrifices less of other goods to produce cocoa than Ghana does.This means cocoa production is relatively cheaper for Nigeria than for Ghana.It does not simply mean Nigeria produces a larger quantity of cocoa.Therefore, the best option is that Nigeria produces cocoa more cheaply than Ghana.Answer:A. Nigeria produces cocoa more cheaply than Ghana