Identify whether demand in the case of each of the following products is likely to

be inelastic, elastic, or unit-elastic.

a. a luxury item with many close substitutes

b. an item that represents a large portion of consumers' incomes and has many

close substitutes

c. a necessity whose demand is being viewed in a short-run time frame

d. a luxury item that represents a large portion of consumers' incomes

Be sure to explain why you believe that the elasticity is what you say it is.