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. Measuring food on the horizontal axis, the joint production possibility frontier A) will have a slope of -2 when less than 20 units of food are produced. B) will have a slope of -3/4 over the entire frontier. C) will have a slope of -1 when less than 20 units of food are produced. D) will have a slope of -1/2 when less than 20 units of food are produced