The tax rates embodied in the federal personal income tax are such that

A.  a rising absolute amount, but a declining proportion, of income is paid in taxes.
B.  the marginal and average tax rates are equal, making the tax progressive.
C.  the average tax rate rises more rapidly than does the marginal tax rate.
D.  the marginal tax rate is higher than the average tax rate, causing the average tax rate to
rise.

D.  the marginal tax rate is higher than the average tax rate, causing the average tax rate to
rise.