Answer:
The correct answer is letter "A": Neither Italy or New Zealand.
Explanation:
Comparative advantage is the ability of an individual or organization to manufacture its products at a lower opportunity cost than its competitors. The scenario does not imply the individual has an absolute advantage. It actually means it sacrifices less to achieve that goal.
Thus, Portugal has a lower opportunity cost than Italy in producing a bottle of wine. Portugal's opportunity cost is 1/2 while Italy's opportunity cost is 2. Neither Italy or New Zealand (or any other country not mentioned in the example) has a comparative advantage in producing wine.