The difference between an elastic and inelastic tax is

A. an elastic tax can be changed by vote in Congress; an inelastic tax can only be altered by popular referendum.

B. an elastic tax increases as income rises; an inelastic tax is the same flat rate for all incomes

C. an inelastic tax is indexed for inflation; an elastic tax is not

D. revenue from an elastic tax is sensitive to changes in the economy but revenue from an inelastic tax is not.