According to the IIA's guidance, internal audit can accept consulting engagements, including providing training, as long as it does not impair their independence and objectivity. In this scenario, the most appropriate action for the chief audit executive (CAE) is to accept the engagement and hire an external specialist to deliver the training. This ensures that the internal audit activity does not compromise its independence by training on areas where they might later need to provide objective assurance. By using an external expert, the CAE ensures the training is conducted by someone with the requisite expertise and without any conflict of interest.
References:
* The Institute of Internal Auditors (IIA), International Standards for the Professional Practice of Internal Auditing (Standards), Standard 1130: Impairment to Independence or Objectivity.
* IIA Practice Guide, "Independence and Objectivity."