Which of the following is not correct? A. Natural monopolies are often subject to regulation.
B. Public ownership is the most common and effective public policy toward monopolies in the United States.
C. Sometimes the best public policy toward a monopoly is to do nothing.
D. Antitrust laws may prevent mergers that would actually raise social welfare.

d

Explanation:

A monopoly is when there is only one firm operating in an industry. there are usually high barriers to entry of firms. the demand curve is downward sloping. it sets the price for its goods and services.

An example of a monopoly is a utility company

A natural monopoly occurs due to the high start-up costs or a large economies of scale.

Natural monopolies are usually the only company providing a service in a particular region  

Antitrust laws prevents mergers that would make the market less competitive. Thus, their aim is to increase social welfare

there was no passage listed but using the process of elimination i'd say it was d. the high economy would do the opposite. i don't see how low prices would affect it. high unemployment is possible but i feel d is the better answer.