4.[International Trade] Suppose there are 2 goods in the world, face masks and hand sanitizers. The table below displays 3 different countries' productivity in making these two goods. Specifically, for each country it shows how face masks and hand sanitizers can be made by one worker, in one day of work. For example, in Country B, 1 worker can produce 400 face masks in one day, or could produce 100 hand sanitizers in one day.