Which of the following is true of a country's production possibilities frontier?

a. A country's production possibilities always equal its consumption possibilities.

b. A country's consumption possibilities can never equal its production possibilities because of leakages in the system.

c. International trade requires that a country's production possibilities exceed its consumption possibilities.

d. The slope of a country's production possibilities frontier is equal to the absolute advantage of producing a particular good.

e. International trade makes it possible for a country's consumption possibilities to exceed its production possibilities.