Final answer:
Country A with an opportunity cost of 0.5 tablets per iPod has a comparative advantage in iPod production, while Country B, with a higher productivity in tablets, has a comparative advantage in tablet production.
Step-by-step explanation:
To determine which country has a comparative advantage in the production of iPods or tablets, one must compare the opportunity costs of producing these goods in each country. Initially, a worker in Country A can produce either 10 iPods or 5 tablets each year, and Country A has total of 100 workers. In Country B, a worker can produce either 2 iPods or 10 tablets, and Country B's workforce increased from 200 to 600 workers.
Comparing the productivities, for Country A, the opportunity cost of producing one iPod is 0.5 tablets (5 tablets / 10 iPods = 0.5 tablets per iPod). For Country B prior to the increase in workers, the opportunity cost of producing one iPod is 5 tablets (10 tablets / 2 iPods = 5 tablets per iPod).
This shows that Country A has a lower opportunity cost for producing iPods and therefore has the comparative advantage in iPod production. With an increase in Country B's workers, these opportunity costs do not change, and Country A still holds the comparative advantage in iPod production, while Country B, due to its higher productivity in tablets (10 tablets per worker as opposed to Country A's 5 tablets per worker), has a comparative advantage in tablet production.
Therefore, the answer is (C) Country A has a Comparative Advantage in iPod production.