Which of the following statements best demonstrates application of due professional care during an assurance...

Demonstrating due professional care during an assurance engagement, according to IIA standards, includes systematically planning, executing, and documenting audit procedures. This ensures that all aspects of the engagement are covered comprehensively and that findings and conclusions are well-supported and credible. This approach aligns with the IIA's definition of due professional care, which emphasizes thoroughness and accuracy in the audit process.

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