Which of the following actions should an auditor take when expanding testing?

When an auditor expands testing, assessing potential risks across a wider scope is the most accurate approach. This method allows the auditor to identify areas of heightened risk or concern that may not have been initially considered. By evaluating a broader range of data and processes, the auditor can uncover potential issues that could affect the reliability of financial reporting or compliance with regulations.

This approach is integral to the audit process, as it ensures that the auditor remains vigilant to any anomalies or risks that may emerge in different areas of the organization. It enhances the auditor's ability to form a comprehensive opinion on the financial statements and helps ensure that the audit is thorough and effective.

In contrast, focusing only on the initial areas identified would limit the auditor's perspective, while randomly selecting new areas without justification may lead to an inefficient use of resources and potentially overlook critical risks. Additionally, limiting testing to just major financial statements would not account for other relevant areas that might impact the overall audit conclusions.