Suppose that gasoline prices increase dramatically this month. Jahzara commutes 100 miles to work each weekday. Over the next few mon ment. These examples illustrate the importance of O a. the definition of a market in determining the price elasticity of demand. Ob, the time horizon in determining the price elasticity of demand. Oc. the availability of close substitutes in determining the price elasticity of demand. d. a necessity versus a luxury in determining the price elasticity of demand