1. Assume the ratio of marginal benefits for three families (A, B, and C) considering building an island wall is MBAMBAMBc = 5:2:1 at any level of wall thickness. At a thickness of O feet, MBA = $1000, MBE- $400, and MBC = $200, and at a thickness of 5 feet, MBA = $500, MB.= $200, and MBe = $100. The marginal cost of building an additional foot of thickness is $800. Graph each family's marginal benefit curve, the demand curve for the public good and the marginal cost curve. a. What is the socially optimal thickness of the wall? b. Suppose families A, B and C are taxed the same dollar amount (S266.67), would they all prefer the socially optimal thickness of the wall? c. What should the tax shares be set at in order to get all three households to prefer the socially optimal thickness of the wall under a unanimity rule