What Role, If Any, Should the Internal Audit Activity Have

What role, if any, should the internal audit activity have in the process of following up on observations and recommendations made by the external auditors?

A) The internal audit activity should have no role in this process in order to ensure independence.
B) The internal audit activity should become involved only if the chief audit executive has sufficient evidence that the follow-up is not occurring.
C) The internal audit activity should review the adequacy and effectiveness of management's follow-up actions.
D) The internal audit activity should become involved only if specifically requested by management or the board of directors.