At school unloading, which sequence best combines securing the bus, student control, and post-unloading checks?

1. Secure the bus, keep students seated until told to exit, supervise orderly unloading, walk through for hidden or sleeping students, then check mirrors before leaving
2. Let students stand before the bus is secured, leave the key in place, and depart as soon as the aisle is empty
3. Unload students through any emergency exit, skip the walk-through, and use the horn before leaving
4. Keep the engine running, let students choose when to exit, and check mirrors only after moving