Documenting anomalies in audit workpapers (D) is the best approach because it ensures traceability, supports findings in the audit report, and allows for future reference if similar issues arise. Even if an anomaly is low-risk, proper documentation is a fundamental audit practice.

Other options:

Reprioritizing testing (A) is a valid audit approach but does not address documentation needs.

Updating the audit plan (B) may be necessary but does not replace documentation.

Prompt remediation (C) is an operational concern but is not always the auditor’s primary role.