In the theory of public goods, the degree of rivalness of any good can be measured by SMC/AC, where SMC is the social marginal cost of the good and AC is its average cost. a. In order for SMC/AC to measure the rivalness of TV broadcasts we cannot define SMC to be the cost to society of an additional broadcast. Explain why not. How must SMC be defined? b. Explain why using SMC/AC to measure rivalness allows us to compare the rivalness of any pair of goods or services that could be provided by a private business. c. Estimate the typical degree of rivalness of an agricultural product like wheat (give a number). Explain how you get this number using your definition in part a. d. Estimate the typical degree of rivalness of the service provided by an internet search engine like that provided by Google. Explain how you get this number using your definition in part a.