Comprehensive and Detailed Explanation:
A shadow payroll is a mechanism used for employees on international assignments who remain on the home country's payroll but must comply with host country tax withholding.
The home country employer processes payroll normally, while the host country imposes local tax liabilities.
The shadow payroll ensures compliance with both home and host country tax regulations.
Option A (Certified Payroll) applies to government contracts.
Option C (Off-Cycle Payroll) refers to out-of-schedule payments.
Option D (Supplemental Payroll) refers to bonus or commission payrolls.
Reference:
IRS - International Payroll and Tax Compliance
Payroll.org - Shadow Payroll and Global Taxation Guidelines