The internal audit activity completed its analysis of sample transactions to determine occurrences of double...

According to IIA guidance, demonstrating due professional care includes adequately planning and supervising the engagement, and documenting the scope and methodology of the audit procedures performed. Option B best demonstrates that internal auditors exercised due professional care by documenting the scope and methodology of the data testing, which is essential for ensuring the engagement's objectives are achieved, and any conclusions drawn are well-supported.

The Institute of Internal Auditors (IIA) - International Standards for the Professional Practice of Internal Auditing.