Please answer question with explanation; I want to know how and where the answers come from

Tuition Subsidies 4. An externality has marginal benefits MB = 48 - 20, marginal social benefits MSB = 48 - Q and marginal costs MC = 12 + Q. a. Illustrate and quantify the cooperative and noncooperative equilibria in this market. b. Illustrate and quantify the efficiency loss. C. The externality problem could be corrected with a per-unit subsidy equal to dollars. d. Update your diagram to show the impact of the subsidy