Comprehensive and Detailed in Depth Explanation:
The "Payroll Activity Report" is the primary tool in Oracle Payroll Cloud for validating and auditing payroll run results. This report provides a detailed breakdown of the payroll process, including earnings, deductions, taxes, and any errors or warnings encountered during the run. It is designed to help payroll administrators diagnose issues before finalizing payments. The "Balance Exception Report" (A) focuses on identifying discrepancies in balances, the "Payroll Balance Report" (B) summarizes balance totals rather than detailed diagnostics, and the "Payroll Data Validation Report" (D) is used for data setup validation, not run result auditing. The Oracle documentation highlights the Payroll Activity Report's role in the "Reviewing Payroll Results" section.