The city is considering have a free live concert in the park - a public good. If the concert takes place it would give Erica's a marginal benefit equal to $30, Julie a marginal benefit equal to $20, Kevin a marginal benefit equal to $60, and Hector a marginal benefit of $40. The marginal social benefit of the concert would be: a. Zero because it is a free concert b. $ 200, i.e. the sum of all their marginal benefits c. $ 120, i.e. the lowest marginal benefit received by any one individual times the number of viewers d. $ 60. i.e. highest marginal benefit received by any one individual