单选题 Which of the following characteristic of perfect competition explains why firms in perfect competition are referred to as price takers?

A. Each firm is small relative to the total market.
B. The demand curve is horizontal for firms in perfect competition.
C. There are many independent firms.

【正确答案】 B

【答案解析】Firms under perfect competition face horizontal (perfectly elastic) demand curves. They can sell all of their output at the prevailing market price, but they will sell nothing if they set their output price above the market price. They are price takers because they have to "take" the market price as a given.