An internal auditor is planning an engagement at a financial institution.

To determine if loans were granted in accordance with the organization's policies, the most effective approach is to validate a sample of loans against the applicable underwriting guidelines. This method allows the auditor to directly assess compliance with the specific criteria set out in the organization's loan granting policies, providing clear evidence on whether the loans meet the required standards.

The Institute of Internal Auditors (IIA) Practice Guide: Auditing Credit Risk Management

IIA Standard 2210 - Engagement Objectives