Theres an additional section at the bottom of the table. 20(tons of SO2) 1200 total cost and 2000 total benefit. Thanks in advance

A local coal-burning power plant spews pollutants into the air, sulfur dioxide (SO2) is one them. The table below provides the total cost and total benefit associated with each level of SO2 emissions. The current level of SO2 emissions is 40 tons. Given this data, what is the efficient level of emissions reduction? (Enter a number only, no units.) emissions level (tons of total cost total benefit SO2) 40 0 35 150 800 30 200 1300 25 500 1850