The figure below shows the production possibilities frontier for a country that produces two goods, wheat and trucks. Use this Figure to answer the following question(s). 4. What could explain the rationale for choosing to produce at point C over point D ? 5. What is the effect on the PPF or the economy's position on the PPF of a recession which increases unemployment nationwide? 6. What is the effect on the PPF or the economy's position on the PPF if a new machine to harvest wheat more efficiently were invented?