14. A paper mill discharges chemicals into a river which washes the shores of a downstream resort area. The private cost, social cost, and marginal benefit associated with the production of paper are given by the following equations: PMC = 5 + Q, SMC = 10 + 2Q, and MB = 35 - 0.50. a) How much output will a competitive free market will produce? b) What is the socially optimal amount of output? 0) Explain how a per-unit tax could be used to correct this