What is the principle of 'progressive braking' taught for smooth and safe vehicle deceleration?

1. Stomp hard on the brake pedal instantly and hold it locked until the vehicle halts
2. Pump the brake pedal rapidly up and down continuously at all speeds
3. Rely solely on the handbrake for routine slowing and use the footbrake only in emergencies
4. Apply gentle initial pressure, increase braking firmly as needed, and ease off slightly just before coming to a complete stop