What is one of the implications if the auditor has not received sufficient returns from unvisited branches?

If the auditor has not received sufficient returns from unvisited branches, it suggests potential weaknesses in the internal controls or record-keeping practices at those branches. This lack of sufficient evidence can raise concerns about the accuracy and completeness of the accounting records. When branches are not fully audited or reviewed, there is a risk that financial results might not accurately reflect the true position of the entity. Consequently, this could lead to a material misstatement in the financial statements, which ultimately affects the auditor's ability to provide a robust opinion.

The other choices do not align with the implications of insufficient returns from unvisited branches. Completing the audit without delays is unlikely when critical information is missing. Similarly, the lack of adequate returns would indeed affect the audit report, as auditors must express their opinion based on sufficient and appropriate audit evidence. Lastly, the adequacy of accounting records is closely related to the financial reporting process and could impact overall performance measures, including directors' remuneration disclosures. Therefore, the inference about potential issues with adequate accounting records is the most pertinent implication in this context.