Final answer:
The option that is not a typical communication between the auditor and the audit committee is the discussion on retention of both client staff and audit firm staff, which is usually a management matter.
Step-by-step explanation:
The question that asks about the typical communication between the auditor and the audit committee relates to the business practices in the field of auditing. The typical communications include the auditor communicating their responsibilities under Generally Accepted Auditing Standards (GAAS), the planned scope of the audit, and all major accounting disagreements with management. However, the discussion regarding the retention of client staff and audit firm staff during the period of the audit, mentioned in option (c), is generally a management responsibility and not typical for communication between the auditor and the audit committee. This type of discussion does not directly involve the auditor unless it specifically pertains to issues that could affect the audit.