According to NA guidance, which of the following actions by the chief audit executive would...

Developing policies and procedures for the internal audit activity is the most effective way for the chief audit executive (CAE) to ensure that internal auditors demonstrate due professional care. This action provides a framework and guidelines that direct auditors on how to perform their duties in accordance with the highest standards of audit practice, including adherence to ethical and professional standards set out by bodies such as the IIA.

IIA Standard 1300 - Quality Assurance and Improvement Program