Which of the following is NOT considered a source of income for a taxpayer?

Tax deductions are not considered a source of income because they are expenses that are subtracted from a taxpayer's total income when calculating their taxable income. Instead of generating income, tax deductions reduce the amount of income that is subject to taxation, which ultimately lowers the overall tax liability.

In contrast, interest, dividends, and rent are all forms of income that taxpayers receive. Interest is earned from savings accounts or investments, dividends are payments made by corporations to shareholders from their profits, and rent is income received from leasing property. Each of these generates additional funds for the taxpayer, making them valid sources of income. Therefore, the distinction lies in the fact that tax deductions are designed to alleviate taxable income rather than serve as revenue.