Which of the following is NOT a responsibility of internal audit?

Internal audit functions primarily focus on evaluating and improving the effectiveness of risk management, control, and governance processes within an organization. Their responsibilities include compliance, training and education related to internal controls and risk management, and conducting investigations into ethical conduct within the organization.

Selecting "investing in securities" as the correct response is appropriate because this function typically falls under the purview of the investment committee or financial management rather than internal audits. Internal auditors are not responsible for making investment decisions or managing investment portfolios. Instead, they may assess how well the organization's investment policies are being followed and evaluate the associated risks, but the actual investment activity is not their responsibility.

Understanding this distinction reinforces the role of internal audit as a watchdog that monitors compliance and organizational integrity, rather than a department that engages in financial investment activities.