The correct answers are D and F.
In audit interviewing practice, open questions are mainly used to get explanation, description, and insight, while closed questions are used to confirm specific facts or verify that the auditor’s understanding is correct. Guidance on audit interviews says auditors should rely mainly on open questions for expanded responses and use closed questions to confirm answers. (The Auditor)
That is why D. To confirm conformity or a non-conformity finding is correct. Once the auditor has gathered evidence, a closed question can be used to verify a precise point, confirm whether a requirement has or has not been met, or make sure the factual basis of a conformity/nonconformity is accurate before recording the finding. ISO 19011 also states that nonconformities and supporting audit evidence should be reviewed with the auditee so the evidence is accurate and understood. (Synersia Foundation)
F. To check that your understanding of a situation is correct is also correct. Closed questions are especially useful at the end of a discussion to confirm the auditor’s interpretation of what was said or observed. This is a standard interview technique in auditing. (Designing Buildings)
Why the other options are not correct:
A. To obtain an overview of how a task is performed is better done with open questions, because the auditor needs explanation and sequence. (The Auditor)
B. To establish communication with the auditee with a view to building trust is usually done through general conversation and open dialogue, not mainly through closed questioning. (The Auditor)
C. To gain greater insight into the operation of a process also requires open questions. (The Auditor)
E. To follow your audit trail generally needs probing and exploratory questions, which are typically open rather than closed. (The Auditor)