Explain the term “service brakes”:

1. Correct answer: A braking system that acts on all the wheels of a vehicle and allows slowing the vehicle down or stopping it in all road conditions.
2. An auxiliary (parking/hand) brake system, designed to prevent accidents, which only acts on the wheels of the rear axle.
3. A braking system that only slows the vehicle down during very steep descents, but is not used for stopping.
4. A braking system that is working at times of danger only and brakes the vehicle until making a complete stop.

WhyService brakes are the system that acts on all the wheels and lets you slow down or stop in any road conditions. The traps are 'only on descents' and 'only the rear wheels'.