How must you behave?

In this situation, you should respond by slowing down to a walking pace and remaining ready to brake.

The reason for this is that there is an object (the red ball) in the road, which might indicate the potential presence of pedestrians or children nearby. By slowing down immediately, you ensure you can stop safely if the situation changes. The requirement to remain ready to brake allows you to respond quickly to any unexpected movements, ensuring safety for all road users.

This approach aligns with German traffic laws, which emphasize pedestrian safety and caution in residential areas where children may be present. Always being prepared to react is crucial to preventing accidents.