单选题 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.
【正确答案】 B
【答案解析】Elasticity of supply equals zero when the supply curve is vertical, indicating perfectly inelastic supply.