A Monopolist Can Earn Economic Profits in the Long Run

A monopolist can earn economic profits in the long run because

A) a monopoly is by definition large, and this gives it the ability to make large profits.
B) a monopoly makes the good or service better than anyone else.
C) barriers to entry prevent new firms from entering the industry.
D) monopolies can legally force people to buy their products and to pay more for them than they are worth.