In Reference to the Federal Income Tax System, a Tax

In reference to the federal income tax system, a tax bracket is

A) the estimated amount of federal income tax firms withhold from their employees' paychecks.
B) the formula the federal government uses to determine the dollar amount of the personal exemption and the amounts taxpayers are allowed for deductions from their incomes.
C) used to determine the average tax rate.
D) the income range within which a tax rate applies.