Which product will have the most elastic demand curve?

A) Gasoline
B) Heating oil
C) Shell-brand gasoline
D) Cigarettes

Shell-brand gasoline will have the most elastic demand curve because it is a specific brand of a broadly available product. Consumers can easily switch to other brands if the price of Shell-brand gasoline increases, making its demand more sensitive to price changes compared to the more generic or necessity-based products listed, such as gasoline in general, heating oil, and cigarettes, which have fewer close substitutes and are more of a necessity for consumers.