Suppose that in a year an American worker can produce 100 shirts or 20 computers and a Chinese worker can produce 100 shirts or 10 computers.
Suppose that without trade the workers in each country spend half their time producing each good.
Use the black point (plus symbol) to indicate this production and consumption point for the United States, and use the grey point (star symbol) to indicate this production and consumption point for China.
If these countries were open to trade, A)China B)the United States would export shirts and A)both countries B)only the United States C)only China would benefit from trade.