What is the basic rule when observing hand signals given by German police officers?

The correct answer focuses on the specific guidance traffic must follow when observing hand signals from German police officers. When a police officer extends their arm, it is important for drivers to understand that this motion indicates that traffic parallel to the outstretched arm is permitted to proceed. This means that if you are in a lane or direction that is aligned with the officer's arm, you can continue driving without stopping.

This rule is crucial for maintaining the flow of traffic and ensuring safety; it allows certain vehicles to move when they might be otherwise hesitant due to the presence of law enforcement. Understanding this directive helps avoid confusion among drivers and aids in the proper orchestration of road traffic, especially at busy intersections or during events where police presence is required to manage flow.

Other potential options do not provide the correct context for how hand signals should be interpreted, as they either suggest a complete stop or restrictions that wouldn't apply to traffic parallel to the officer's arm.