When demand is perfectly inelastic:
A) the demand curve is perfectly vertical.
B) the demand curve is perfectly horizontal.
C) the measured elasticity is exactly −1.
D) the response to a change in price is immediate.

Question

Quizplus · Accepted Answer

When demand is perfectly inelastic, it means that quantity demanded does not change in response to a change in price. This is represented graphically by a completely vertical demand curve, as shown in the extreme left of the elasticity spectrum. Therefore, choice A is correct as it represents the perfectly inelastic demand curve.

When Demand Is Perfectly Inelastic