Suppose pollution, E, has marginal damages and marginal cost of reducing emissions as follows: MD =4 +2E MC -4 (6 +1) - 6E The regulator is uncertain about the value of r. but guesses that it is either 0 or 6. I a) On two separate graphs, plot the marginal damages and the marginal costs if r is low and the marginal costs if r is high. (One graph for each value of r.) What is the optimal amount of emissions if r is low and if'r is high? Show on your graphs. b) Calculate the Pigouvian tax that will achieve the optimal emissions if r is low if r is high. Calculate is the total cost of emissions in this economy under these two optimal scenarios