What defines a school bus?

A school bus is specifically defined as a vehicle designed and used primarily for transporting students to and from school, as well as to related activities such as field trips or sports events. This definition emphasizes the bus's primary function of serving the educational system and ensuring the safe transportation of children.

The primary focus is on the context of student transport, which sets school buses apart from other types of vehicles. While a vehicle could also be used for public transport, merely having that function does not qualify it as a school bus. Similarly, while some vehicles can accommodate a wide range of passengers, the defining factor of a school bus is its dedicated purpose. Furthermore, a vehicle solely for school staff, while it may operate within the school environment, does not meet the criteria of specifically serving the needs of students. The emphasis here is on the target users of the vehicle, reinforcing why option B is the most accurate definition of a school bus.