Final answer:
A person has a comparative advantage in producing a good if they can do so at a lower opportunity cost than others, which is the basis for beneficial trade between countries.
Step-by-step explanation:
A person has a comparative advantage in producing a particular good if that person can produce it at a lower opportunity cost than anyone else can. Therefore, the correct answer is A: can produce it at lower opportunity cost than anyone else can. An absolute advantage refers to the ability of a person or economy to produce more of a good per unit of labor than another, while a comparative advantage means being able to produce a good at a lower opportunity cost, which represents the cost of not producing the next best alternative.
Countries or individuals gain from trade by specializing in goods where they hold a comparative advantage and trading for other goods. Global production and levels of consumption can thereby increase. Opportunity cost is a fundamental concept in understanding comparative advantage.