Which of the Following Would Create a Natural Monopoly

Multiple Choice

Which of the following would create a natural monopoly?

A) An exclusive right granted to supply a good or service.
B) A patent granted the producer of the good or service.
C) Technology enabling a single firm to produce at a lower average total cost than two or more firms.
D) The requirement to obtain a government licence before a firm can sell the good or service.
E) Ownership of all the available units of a necessary input.