Which of the Follow Is NOT a Characteristic of Natural

Which of the follow is NOT a characteristic of natural monopoly?

A) Two or more firms experiencing economies of scale can produce the industry output at lower total cost than if a single firm produces the industry output.
B) One firm can produce the industry output at a lower total cost than two or more firms.
C) One firm is the technically efficient way to organize production.
D) Production of the industry output is characterized by cost subadditivity.