Suppose the production possibilities for two countries, producing either food or clothing, are shown ...

Suppose the production possibilities for two countries, producing either food or clothing, are shown in the above figure. They can each produce any linear combination as well. Assuming free trade between these two countries, Canada will produce food
A) as long as any positive amount of food is demanded.
B) as long as more than 10 units of food are demanded.
C) as long as people are willing to give up at least 1 unit of clothing to get a unit of food.
D) as long as people are willing to give up more than 1/2 unit of clothing to get a unit of food.