An Industry Is a Natural Monopoly When Which of the Following

Multiple Choice

An industry is a natural monopoly when which of the following is(are) true?
(i) a single firm will supply a good or service at a socially optimal quantity
(ii) a single firm can supply a fixed number of goods or services at a smaller cost than could two or more firms
(iii) a single firm can produce additional units at a smaller marginal cost

A) (i) and (ii)
B) (ii) only
C) (ii) and (iii)
D) (iii) only