Which one of the following techniques can be used to check whether the existing internal controls of a company are operating effectively?

An audit is one of the techniques that can be used to check whether the existing internal controls of a company are operating effectively. Here are the steps:

1. Planning: The auditor needs to understand the company's operations, identify areas of high risk, and plan the audit accordingly.

2. Testing: The auditor tests the effectiveness of the internal controls by checking records, observing processes, and performing other audit procedures.

3. Evaluation: The auditor evaluates the results of the tests to determine whether the internal controls are operating effectively.

4. Reporting: The auditor prepares a report detailing the findings of the audit, including any weaknesses in the internal controls and recommendations for improvement.

5. Follow-up: The auditor follows up to ensure that the company has implemented the recommended improvements.