Internal auditors must identify which of the following types of information to achieve the engagement's objectives?

To achieve the engagement's objectives, internal auditors must focus on obtaining sufficient information. This means that the data gathered must be adequate and comprehensive enough to support the findings and conclusions of the audit. Sufficient information enables the auditor to assess risks, evaluate controls, and provide actionable recommendations. It ensures that the conclusions drawn from the audit are based on a solid foundation, minimizing the likelihood of overlooking critical issues or making unsupported assertions.

While the other types of information such as timely, relevant, and confidential are indeed important in the context of internal audits, they do not encompass the primary requirement to ensure that the information is adequate in quantity and quality to support the audit's objectives. Timely information ensures that the data is up-to-date, relevant information makes sure that the data pertains to the audit's focus area, and confidential information concerns the sensitivity of the data being used. However, without sufficient information, the audit may lack credibility and depth, rendering its conclusions less useful or actionable.