47. Which of the following government environmental policies would likely be the most efficient in reducing emissions and ensuring that the economy functions close to capacity? (A) Price carbon more efficiently through taxation and the trading of carbon credits. (B) Require all environmentally polluting firms to cease business within five years. (C) Require that the higher cost of power generated from coal equal the cost of solar-generated power. (D) Impose no controls and let market forces prevail. GO ON TO THE NEXT PAGE