When is it illegal to pass a school bus?

Answer: A — when it has stopped and its red lights are flashing

Passing a school bus is illegal when the bus has stopped and its red lights are flashing. This law is designed to protect children who may be entering or exiting the bus. The flashing red lights serve as a clear signal that all other vehicles must come to a complete stop, allowing children to safely cross the street and ensuring that they are not in danger of being hit. When a school bus is in motion, it is typically less of a concern for children on foot. Similarly, if there are no other vehicles around, it might seem like passing would be safe, but the law prioritizes the safety of children above all else, meaning that drivers must always adhere to the stop requirement when the bus is flashing its lights. Additionally, the act of unloading passengers occurs when the bus is stopped with its red lights on, reinforcing the necessity of stopping for the safety of those exiting the bus.