What Distinguishes a Natural Monopoly from a Monopoly

Multiple Choice

What distinguishes a natural monopoly from a monopoly?

A) One firm can supply the entire range of demand (picture a downward-sloping industry demand curve) at a lower ATC than can any number of firms.
B) One firm has exclusive access to raw materials.
C) The firm has been issued a patent on a cost-saving technology.
D) The government regulates the industry, allowing only one firm to produce.
E) The market contained two firms that merged to become one.