The price the federal government charges the coal companies should A. not include this cost because including this cost makes the marginal social cost less than the marginal social benefit and economic efficiency would not be improved. B. include this cost because including this cost makes the marginal social cost greater than the marginal social benefit and economic efficiency would be improved. C. include this cost because including this cost makes the marginal social cost equal to the marginal social benefit and economic efficiency is achieved. D. not include this cost because including this cost makes the marginal social cost equal to the marginal social benefit and economic efficiency is not achieved