When operating a passenger bus in winter during icy and snowy weather conditions, what safety measures should the driver take regarding passenger boarding and vehicle maneuvering?

1. Rush passengers onto the bus quickly and accelerate rapidly to avoid freezing
2. Clear snow and ice from entrance steps, remind passengers to watch their footing, ensure all passengers are securely seated/braced before pulling away, and maintain double the normal following distance
3. Apply sudden emergency braking at every stop to test tire grip
4. Turn off the cabin heater to prevent window fogging