单选题 Which of the following most accurately describes a market structure that has one seller of a specific, well-defined product that has no good substitutes?
  • A. Oligopoly.
  • B. Monopoly.
  • C. Monopolistic competition.
【正确答案】 B
【答案解析】A monopoly is characterized by one seller, a specific and well-defined product for which there is no good substitutes, and high barriers to entry.