Final answer:
Confirmation is particularly relevant for verifying the existence of accounts receivable when an auditor is assessing the accuracy of a company's financial statements.
Step-by-step explanation:
Confirmation is most likely to be a relevant form of evidence with regard to assertions about accounts receivable when the auditor has concerns about the receivables' existence. When auditing, confirmation involves asking external parties to verify the existence of transactions and balances.
This external evidence provides a high level of assurance that the receivables exist and are not just fabricated figures on the balance sheet. For instance, an auditor might send confirmation letters directly to the clients who owe money to the company being audited to confirm the balances they owe. This type of verification is less concerned with valuation, classification, or completeness, but rather with the straightforward factual existence of the receivables.