What must you do as driver of a school bus before leaving a bus stop?

You answered correctly by selecting all three necessary actions. As a school bus driver before leaving a stop, you must ensure all doors are properly closed for safety, check carefully that no child is standing or crossing in front of the bus to prevent accidents, and switch off the hazard warning lights once the boarding or exiting process is complete. These rules help protect children and ensure safe operation of the bus as you continue driving. Always follow all these steps to comply with German traffic regulations and guarantee passenger safety.