Suppose a factory emits pollution into the air during its production process. The demand​ (D) for its output​ (Q) is p​= 2400- Q, its marginal cost of production​ (MC) is MC​= 0.8Q, and the social marginal cost of production ​(​) isMC'= 1Q. If the government were to achieve the social optimum amount of production with an emissions fee, then what would be the optimal​ fee? The optimal fee would be____________ ​$ nothing per unit of output. ​(Enter a numeric response using a real number rounded to two decimal​ places.)