Which of the following is an effective approach for internal auditors to take to improve collaboration with audit clients during an engagement?

1. Obtain control concerns from the client before the audit begins so the internal auditor can tailor the scope accordingly.

2. Discuss the engagement plan with the client so the client can understand the reasoning behind the approach.

3. Review test criteria and procedures where the client expresses concerns about the type of tests to be conducted.

4. Provide all observations at the end of the audit to ensure the client is in agreement with the facts before publishing the report.