Suppose that each is currently assigning 5 units of labor to guns and 5 units of labor to butter. If they instead specialized based on comparative advantage, the total amount of guns and butter produced (by both countries) would change by how much?

aButter would increase by 5 and guns would increase by 5

bButter would increase by 5 and guns would increase by 0

cButter would increase by 10 and guns would increase by 5

dButter would increase by 5 and guns would increase by 10