Why Should We Never Assume That an Inelastic Demand Curve

Multiple Choice

Why should we never assume that an inelastic demand curve is a perfectly inelastic demand curve?

A) because there has never been evidence of a perfectly inelastic demand curve.
B) because an inelastic demand curve may be perfectly inelastic at some times but not others.
C) because perfectly inelastic demand curves are rare.
D) because an inelastic demand curve may be elastic at high prices.