Under what circumstances can the Department of Motor Vehicles cancel a school bus certificate?

The correct choice focuses on the importance of adhering to the restrictions imposed on a school bus certificate. When a driver violates a restriction listed on their certificate, it signifies a disregard for the regulations that are essential for ensuring safety within the context of operating a school bus. The Department of Motor Vehicles (DMV) sets these restrictions to protect not only the driver but also the passengers, which include vulnerable school children.

As a result, violating these restrictions is taken very seriously and can lead to the cancellation of the certificate. This measure helps maintain a higher standard of safety and accountability among individuals responsible for transporting students, reflecting the state's commitment to ensuring that only those who adhere to the guidelines are allowed to operate these vehicles.

Other factors, while potentially significant in an individual’s qualifications to drive a school bus, do not carry the same immediate consequence of cancellation as violating a legal restriction.