Suppose the government requires each firm to reduce sulfur dioxide emissions by an equal amount such that total emissions are reduced by 7.0 million tons per year. Is this approach necessarily economically efficient? This command-and-control approach is efficient because reducing sulfur dioxide pollution by 7.0 million tons per year is where the marginal cost and marginal benefit of pollution reduction are equal. is efficient because each firm is reducing pollution by the same amount. is not efficient because some firms may still be generating pollution. is not efficient because firms can have different costs of reducing pollution. is efficient because it does not require the government to know the firms' cost of reducing pollution.