Final answer:
The status of the real estate licensee's expired license on October 1 is 'Involuntary inactive,' meaning the licensee cannot engage in real estate activities requiring a license until renewal.
Step-by-step explanation:
When a real estate licensee's license expires after a period of activity, such as the scenario described where the license expired on September 30, the status of the license on October 1 is typically Involuntary inactive. This status indicates that the license is not currently valid due to the expiration and the licensee is not permitted to engage in real estate activities that require a valid license. However, the licensee may have a grace period or process to renew the license without penalty or with a late fee, depending on the specific regulations of the governing real estate authority of the state.