What is the basic rule regarding the hand signals of German police officers?

Answer: C — Traffic parallel to the officer's arms may proceed

The fundamental principle regarding the hand signals of German police officers is that traffic parallel to the officer's arms may proceed. This means that when an officer extends their arms outwards to signal traffic, only the vehicles moving in the same direction as the officer's arms are allowed to continue. This is a critical aspect for drivers to understand, as it ensures that traffic flows smoothly while also maintaining safety at intersections or during traffic control situations. This signaling system allows police officers to manage traffic effectively, ensuring that motorists understand when they are allowed to proceed and when to stop. The direction of the officer’s arms indicates the flow of traffic that is clear to move, which is essential in maintaining an orderly environment on the roads.