All of the following withholding methods use the Tentative Withholding Amount in the calculation of...

Comprehensive and Detailed in-Depth Explanation:

The Tentative Withholding Amount is a calculated figure used in certain methods to determine the appropriate amount of federal income tax to withhold from an employee's wages. The aggregate, percentage, and wage bracket methods all utilize this concept. However, the mandatory flat rate method applies a fixed percentage (currently 22%) to supplemental wages without considering a tentative withholding amount. Therefore, the correct answer is D. mandatory flat rate.