The scenario described involves a violation of the principle of confidentiality as defined in The IIA ' s Code of Ethics. The internal auditor misused information obtained during the course of an audit (salary data of colleagues) for personal gain (requesting a salary raise). This breaches the ethical principle of confidentiality, which mandates that auditors respect the value and ownership of information they receive and do not disclose information without appropriate authority unless there is a legal or professional obligation to do so.
The IIA ' s Code of Ethics on Confidentiality.

When a risk assessment shows that the cost of addressing a particular risk is greater than the perceived benefit, the appropriate risk response approach is to accept the risk. Risk acceptance means acknowledging that the risk exists but deciding not to take any action to mitigate it, usually because the cost of mitigation is higher than the potential impact. This approach is a rational decision when the risk is deemed to have a low likelihood or impact, or when other controls are considered sufficient.
The IIA Standards: Standard 2120 - Risk Management: "The internal audit activity must evaluate the effectiveness and contribute to the improvement of risk management processes." COSO ERM Framework: Discusses risk response options including risk acceptance as a viable strategy when the cost-benefit analysis justifies it.

The statement that articulating measurable objectives is part of internal control is true. A system of internal control is designed to help an organization achieve its objectives, and these objectives need to be clearly stated and measurable to effectively assess and control risks related to them.
COSO Framework for Internal Control, which emphasizes the importance of clear, measurable objectives in effective internal control systems.

The scenario where managers who have been with the organization for several decades become aware that newly hired, younger managers are being moved more quickly into senior positions best illustrates a rationalization as the root cause of potential fraud. This situation could lead these managers to feel justified in committing fraud, believing they are undervalued or unfairly treated, which is a common form of rationalization in fraudulent activities.
Fraud triangle theory, which includes rationalization as one of the key elements leading to fraud, as discussed in various IIA resources on fraud and ethical behavior.