Consider 5 farmers located close to a lake. The lake is used by 5 recreational users for swimming. The farmers use fertilizer with marginal benefits MB = 12 - 2x where x is the amount of fertilizer applied. The cost per unit of fertilizer is 4. The fertilizer runoff into the lake reduces the water quality. The marginal damage from fertilizer use through reduced water quality is MD = 0.08 X for each of the recreational users. X is the total amount of fertilizer that all farms combined apply. The government decides to implement a cap and trade system for fertilizer use. What is the equilibrium price of fertilizer quota if the cap and trade system implements the efficient solution?