Which of the following is NOT a type of withholding tax?

Sales tax stands out as the correct answer because it fundamentally operates differently from withholding taxes. Withholding taxes are amounts subtracted from an employee's paycheck by the employer, intended to cover income taxes and certain social security contributions before the employee receives their net pay. They are directly related to income earned by an individual.

In contrast, sales tax is a consumption tax imposed on the sale of goods and services, collected at the point of sale by retailers and paid by consumers, rather than being deducted from wages. Thus, it does not involve the employment relationship or direct income withholding from paychecks, which is why it is not categorized as a type of withholding tax.

Federal income tax, state income tax, and social security tax all directly involve employer withholding from employee earnings, thus fitting the criteria of withholding taxes.