Assuming that we can properly measure ability to pay, how do we use th

Assuming that we can properly measure ability to pay, how do we use the principle of vertical equity to determine how much someone with greater ability to pay should pay in taxes?

a. By integrating it with the principle of horizontal equity.
b. Through reference to the benefit principle.
c. By looking at elasticities of demand for various income quintiles for the good in question.
d. We cannot use the principle of vertical equity to answer this question.

ANSWER

d