Final answer:
The internal auditor violated the principle of confidentiality by sharing sensitive information with a close personal friend who is the division's CFO. The correct option is C) confidentiality.
Step-by-step explanation:
When an internal auditor, who is auditing a division, reveals confidential information to the division's chief financial officer who is a close personal friend, the auditor violates the principle of confidentiality.
According to the Institute of Internal Auditors (IIA) Code of Ethics, confidentiality must be maintained, and no internal audit information should be disclosed without proper authority or unless there is a legal or professional obligation to do so.
Furthermore, the sharing of sensitive information, like impending changes in divisional leadership, could potentially affect the outcomes of critical contract negotiations and thus represents a breach of ethical conduct.