Final answer:
The objective of an auditor as stated in AU-C 540 is to obtain evidence that accounting estimates are reasonable and disclosures are adequate, reflecting both the quality of the estimates and the completeness of the related financial information. Option 3.
Step-by-step explanation:
AU-C 540 Auditing Accounting Estimates, Including Fair Value Accounting Estimates, and Related Disclosures states the objective of the auditor is to obtain sufficient appropriate evidence that both accounting estimates are reasonable, and disclosures are adequate(3). This indicates that it is not enough for the estimates to be reasonable in isolation; the associated disclosures must also be comprehensively and appropriately presented. As an auditor, when evaluating accounting estimates, one should assess the methods, assumptions, and data used in their preparation, as well as consider whether the related disclosures in the financial statements are in accordance with the applicable financial reporting framework.