Which of the following statements is not correct? a. Both corrective taxes and tradable pollution permits reduce the cost of environmental protection and thus should increase the public's demand for a clean environment. b. Tradable pollution permits have an advantage over corrective taxes if the government is uncertain as to the optimal size of the tax necessary to reduce pollution to a specific level. c. Both corrective taxes and tradable pollution permits provide market-based incentives for firms to reduce pollution. d. Corrective taxes set the maximum quantity of pollution, whereas tradable pollution permits fix the price of pollution.