Which action best exemplifies a corrective control?

Corrective controls focus on addressing and rectifying issues that have already occurred within an organization. The action of updating internal procedures after an identified issue serves as a direct response to rectify the problem, ensuring that similar issues do not occur in the future. This is a proactive measure that allows an organization to learn from its mistakes and enhance its processes, ultimately strengthening the internal controls.

In contrast, conducting an internal audit involves assessing current processes and controls but does not directly correct an issue unless changes are made based on the findings. Reviewing financial diversification strategies focuses on strategic planning rather than directly addressing identified deficiencies. Establishing a marketing plan is a forward-looking action that does not relate to correcting past issues within internal controls or procedures. Thus, updating internal procedures stands out as the clear example of a corrective control.