Suppose the city of austin, tx chooses to regulate the number of street vendors operating near the university of texas by requiring each vendor to own a permit in order to operate. the city gives free permits to all existing vendors and announces that no new permits will ever be issued. prior to regulation, the costs (including implicit costs) of operating were $85,000 and revenues were $150,000. the city ordinance allows the permits to be bought and sold without restriction. the permits have no expiration date. the interest rate is 10 percent. after regulation, existing street vendors earn an

a. accounting profit of zero.

b. economic profit of $130,000.

c. economic rent of $65,000

d. economic loss.