Which of the following is required to achieve progressivity for a particular tax?

A)

an average tax rate above the marginal tax rate (implying that the average tax rate is falling with income)

B)

a marginal tax rate equal to the average tax rate (implying that the average tax rate is falling with income)

C)

a constant tax rate for all incomes

D)

a marginal tax rate above the average tax rate (implying that the average tax rate is rising with income)

E)

a marginal tax rate equal to the average tax rate (implying that the average tax rate is rising with income)