Which of the following is not an example of a deduction?

a) state tax payments
b) donation to charity
c) taxable income
d) interest on a mortgage

The correct answer is C) taxable income.

Taxable income is not an example of a deduction.

Generally speaking, in the United States, a tax deduction is the amount of money the Internal Revenue Service allows you to subtract from the AGI (adjusted gross income). This way you can have a low taxable income. You can have deductions on state tax payments, donations to charity, or interest on a mortgage.