4. Suppose that two countries, Machineland and Farmland, have the following production possibility curves: (109-1) 200 200 T . 8 (50, 150) Machines 100 4 20, 100) Machines 100 D(50, 50) C 150, 10) 100 200 100 200 Food Food Machineland Farmland a. Explain how these two countries can move from points.d and C where they currently are, to points $ and D. b. If possible, state by how much total production for the two countries has risen. c. If you were a trader, how much of the gains from trade would you deserve for discovering this trade? d. If the per-unit cost of production falls as output rises, how would the analysis change