Suppose That Juan Carlos Is Filling Out a Survey That

Suppose that Juan Carlos is filling out a survey that he received in the mail.The survey asks him what he would do if the price of his favorite toothpaste increased.Juan Carlos reports that he would switch to a different brand.The survey asks what he would do if the price of all toothpastes increased.Juan Carlos reports that he must use toothpaste,so he would have to adjust his spending elsewhere.These examples illustrate the importance of

A) changes in total revenue in determining the price elasticity of demand.
B) a necessity versus a luxury in determining the price elasticity of demand.
C) the definition of a market in determining the price elasticity of demand.
D) the time horizon in determining the price elasticity of demand.