Final answer:
If the service line disconnects while driving, the brakes will fail.
Step-by-step explanation:
If the service line disconnects while you are driving, it will cause the brakes to fail, resulting in the vehicle not being able to stop properly.
The service line is part of the braking system in a vehicle and is responsible for transmitting the pressure from the brake pedal to the brakes on each wheel. If the service line disconnects, it will lead to a loss of pressure in the brake system, causing the brakes to fail.
Therefore, the correct answer is 3) The brakes will fail.