(a) Before the renewable fuels mandate, the corn market supplies 20 million bushels of corn at a price of $20 per bushel, where D_c1 intersects S_c1. When the demand for corn shifts out to D_cF, corn’s price increases to $28 per bushel, and its quantity increases to 28 million bushels.(b) Wheat, a substitute good for corn, is at an initial equilibrium of 20 million bushels at $20 per bushel, where initial demand curve D_w1 and supply curve S_w1 intersect. When the renewable fuels mandate increases corn prices, the demand for wheat increases to D_wF. The wheat market now supplies 24 million bushels of wheat at a price of $24 per bushel, where D_W2 intersects S_w1.