问题
单项选择题
Which of the following most accurately describes elasticity of supply Elasticity of supply is the percentage change in the quantity supplied divided by the percentage change in:（）
A. price and it equals zero when supply is perfectly elastic.
B. price and it equals zero when supply is perfectly inelastic.
C. quantity demanded and it equals infinity when supply is perfectly inelastic.
答案
参考答案：B
解析：
Elasticity of supply equals zero when the supply curve is vertical, indicating perfectly inelastic supply.