Use the following table to answer the next question(s). The data in the table show the marginal costs and marginal benefits to a city for five different levels of pollution abatement. Quantity of Pollution Marginal Marginal Abatement Cost Benefit 900 tons $400,000 $100,000 800 tons 300,000 150,000 700 tons 200,000 200,000 600 tons 100,000 250,000 500 tons 50,000 300,000 Refer to the above table. If the city seeks an optimal reduction of the externality, then it will select how many tons of pollution abatement: 600 500 0 700 0800