Please provide a detailed explanation to the following question and explain why the other answer choices are wrong.

[17] If a subsequently discovered fact becomes known to the auditor before the release of the audit report, the auditor should A. Modify the opinion and dual date the audit report. No additional audit procedures are required. B. Date the audit report as of the original date of the auditor's report and caption the note disclosing the subsequent event as being subsequent to the completion of the audit procedures. C. Not modify the audit opinion if the event is properly disclosed and date the audit report as of the original date of the auditor's report. D. Either dual date the audit report or date the audit report as of the time of the completion of the extended audit procedures