The descriptions refer to different approaches to regulating natural monopolies. For each, select the corresponding term a. Firms charge a price that allows them to earn only a normal economic profit. b. The government operates a monopoly before any private business enters the market or purchases an existing monopoly. c. The government breaks up a monopoly into smaller firms to allow other smaller firms to enter the market. d. Firms are directed to charge the price associated with the extra cost of making each unit. This pricing rule often leads to firms earning a negative profit