After the report release date, the auditor may become aware of facts that may have affected the financial statements and auditor's report, had the auditor known the facts at the time of issuance. With regard to this situation, which of the following statements is true?

a$.$ Because such facts become known after the report release date, the auditor cannot reasonably be held accountable for these issues; no action is required on the part of the auditor.

b$.$ If the auditor decides that steps should be taken to prevent further reliance on the financial statements and audit report, the client is advised to make appropriate and timely disclosure of these new facts.

c$.$ If such facts would have been investigated had they been known at the report date, the auditor should determine whether engagement personnel are competent and qualified to perform audits; action is required on the part of the auditor to assess whether engagement personnel should be retained to work on the engagement in the subsequent year.

d$.$ If the auditor decides that steps should be taken to prevent further reliance on the financial statements and audit report, the auditor should notify the audit committee immediately; no action beyond this is required on the part of the auditor because of confidentiality concerns.