Which of the following offers the best evidence that the internal audit activity has achieved...

Organizational independence for the internal audit activity is best evidenced when the chief audit executive (CAE) reports functionally and administratively to the CEO. Functional reporting to the CEO or equivalent position ensures that the internal audit activity has direct access to top management, which supports its independence and the ability to carry out audits without undue influence from management. Administrative reporting to the CEO also helps align the internal audit function’s objectives with those of top management, reinforcing its autonomy and authority within the organization.

IIA's International Standards for the Professional Practice of Internal Auditing regarding organizational independence.