Which of the following is not a prohibited practice for the driver of a bus?

Using your seatbelt while operating a bus is not a prohibited practice; in fact, it is a safety requirement. Seatbelts are designed to protect drivers in case of accidents or sudden stops, reducing the risk of injury. Drivers should wear their seatbelts at all times for their own safety and to comply with legal regulations.

The other practices mentioned, such as using a cellphone, eating, or allowing passengers to distract you, are prohibited because they can significantly impair the driver's attention and control over the vehicle. These actions increase the risk of accidents and jeopardize the safety of all passengers and other road users. Ensuring that drivers focus solely on driving without distractions is vital for maintaining safe transportation.