Which of the following documents is at risk of being seized during a station suspension?

The document that is at risk of being seized during a station suspension is the Certification of Appointment. This certification is crucial as it officially designates an individual or a facility as a certified inspection station. When a station is suspended, it indicates that there are compliance issues or violations pertaining to the inspection process, which necessitates the removal of the authority granted by the Certification of Appointment.

When an inspection station's certification is suspended, the state takes steps to ensure that the station can no longer operate in an official capacity, as it could potentially pose a risk to public safety. The suspension affects the station’s ability to perform inspections lawfully, hence the certification is subject to being seized alongside the operational rights of the station.

The other documents mentioned, such as a driver's license, vehicle registration, and insurance documents, are important for vehicle operation and ownership but do not pertain directly to the authorization of inspection stations. These documents are not typically affected by the suspension of a station’s operating authority.