Which of the Following Would Create a Natural Monopoly

Multiple Choice

Which of the following would create a natural monopoly?

A) ownership of all the available units of a necessary input
B) an exclusive right granted to supply a good or service
C) requirement of a government license before the firm can sell the good or service
D) technology enabling a single firm to produce at a lower average total cost than two or more firms
E) a patent granted the producer of the good or service