You want to tow a trailer. What must you note regarding the electric cable between the towing vehicle and the trailer?

The selected combination of answers is correct because each point addresses an important aspect of towing trailers according to German traffic regulations.

1. The electric coupling devices must not be damaged to ensure proper electrical connection and functionality. Any damage could result in failures in the lighting system, which is critical for safety.

2. It is essential for the onboard voltage of the towing vehicle and trailer to match. Mismatched voltages could cause electrical issues, including failure of lights and indicators, which can lead to dangerous situations on the road.

3. Checking the proper functioning of the lighting systems before starting the journey is crucial. All lights, including brake lights and indicators, must be operational to ensure that other road users are aware of your actions and intentions.

Understanding and adhering to these regulations helps ensure not just the safety of the towing vehicle and trailer but also the safety of all road users.