The **autonomous emergency braking system (AEB)** is an active safety device that helps prevent collisions. This system uses a **radar** to measure the distance between your vehicle and the one in front.

- **Operation of the AEB**:
- When the AEB detects that the distance between vehicles is too short and there is a risk of collision, it first **warns the driver** with a voice and a sound.
- If the driver does not respond to these warnings, the system **performs an emergency braking** automatically to avoid the accident.

This process ensures that the driver has the opportunity to react before the system intervenes, which makes the correct option the one that describes that the AEB first warns the driver and, if there is no response, performs the emergency braking.