2. The private marginal benefit for commodity X is given by MPB=10-X, where X is the number of units consumed. The private marginal cost (PMC) of producing X is constant at $4. For each unit of X produced, an external cost of $2 is imposed on members of society. a. In the absence of any governmnent intevention, how much X is produced? (10 points) b. What is the socially efficient level of production of X? (10 points) c. What is the gain to society involved in moving from the inefficient to the efficient level of production? (10 points)