As well as glaciers and people
Answer: A. Comparative advantage, because products can be made more efficiently in the southern United States and Mexico. Operating costs and wages are lower, and the manufactured products are easily transported to major United States markets.
Explanation: Comparative advantage of a location is the ability to produce a good at lower cost than elsewhere. Lower wages, as well as lower operating costs in Mexico and Southern states achieve this comparative advantage by reducing total cost. Their locations are still quite close to the Midwest and North east, in contrast with popular outsourcing locations such as China. It therefore makes sense to relocate factories to these locations.