Which of the Following Does NOT Influence the Price Elasticity

Which of the following does NOT influence the price elasticity of demand?

A) Whether the good is a necessity or a luxury.
B) The amount by which the demand curve shifts when the price of another good changes.
C) The number of substitutes available to consumers.
D) The time period buyers have to respond to a price change.
E) The price of the good relative to total income.