A - Alarm
Alarm - The two basic types of car alarm are perimetric and volumetric. The former protects the car's perimeter (going off if a window is broken, for example) while the latter protects the interior. In many cases, when the two are combined, you can turn off the volumetric protection to allow a person or animal to stay in the car for a short time, even though the alarm has been set. The most advanced systems incorporate a motion sensor, which guards against the car being towed away.
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