【正确答案】 C

【答案解析】Demand curves are not observable so a monopolist must search for the profit maximizing price. Because demand information is not perfect, a monopolist is a price searcher. The other statements are false. Although a monopolist can earn positive economic profits in the long run, they are not guaranteed profit. If average total costs exceed price, the monopolist will lose money. A monopolist maximizes profit where marginal revenue equals marginal cost. A monopoly may be defined as a single seller of a well-defined product for which there are no good substitutes.