Which of the following would be least appropriate in the auditor's test of controls over accounting estimates? 1. Confirmation of approval of the estimate by the Board of Directors. 2. Review of documentation to determined that the estimate is properly reviewed and authorized. 3. Review of processes used to determine if there are changes in the economic environment that impact the estimate. 4. Review of processes to approve changes to the estimate process. O 1 O 2 O 3 o O 4