Coal burning power plants are a major source of mercury air pollution because mercury is contained in coal and is released when the coal is burned. Suppose that the price of key inputs used to remove mercury from coal falls so that the marginal cost of abatement (MCA) for mercury falls for all the power plants. A) Show how the industry will adjust to this reduction in abatement costs assuming that Mercury emissions by power plants are subject to a tax of $t per ton which does not change. Use a graph and verbal description to show how the lower MCA for the plants affects: (1) the marginal cost of abatement in the market. (2) the total level of abatement (AT) and emissions (ET) with the tax of $t (3) the allocatively efficient level of pollution abatement (AE). B) In general, besides a Pigouvian tax, the government has alternative instruments at its disposal to make firms reduce pollution. Provide a list of these instruments. What is the ranking of these instruments regarding how they incentivize innovations? Provide an intuitive discussion to justify that ranking