问题
单项选择题
Which of the following is NOT a characteristic of perfect competition（）
A. The products produced within a given market are homogenous.
B. The demand curve for an individual firm is a vertical line.
C. The size of each firm is small relative to the size of the overall market.
答案
参考答案：B
解析：
Under perfect competition individual firms have no control over price resulting in a demand schedule that is perfectly elastic or horizontal.