Why do internal auditors review the adequacy of a company's internal control system?

The focus of internal auditors reviewing the adequacy of a company's internal control system primarily revolves around the goal of determining if the company's objectives are met efficiently. By assessing internal controls, auditors can evaluate whether the systems in place effectively prevent errors, fraud, and inefficiencies that could hinder the organization's performance.

An internal control system is designed to help a company achieve its operational, financial, and compliance objectives. If these controls are adequate and functioning properly, the organization can trust that its objectives are being pursued efficiently and effectively. This involves not just meeting minimum compliance standards but also optimizing processes to enhance overall performance.

The review helps in identifying weaknesses or gaps in the control system that could be improved to facilitate better performance toward these objectives. Thus, option C reflects the essential role of internal auditors in promoting operational efficiency and effectiveness while ensuring that strategic goals are fulfilled.