Suppose that there are two local busing companies that contribute to the air pollution in a city. The marginal benefit from air pollution reduction is equal to hailB=-2Q. where Q is the amount of air pollution reduction. The marginal cost of reducing air pollution for bus company A is MC=4Q and the marginal cost of reducing air pollution for bus company B is MC=Q a. What is the socially optimal amount of air pollution reduction? b. Is it cost-effective to have each of the bus companies reduce air pollution by equal amounts? Why or why not\