What does a sign prohibiting U-turns indicate?

A sign prohibiting U-turns indicates that drivers are not allowed to perform U-turns at that specific location. This restriction is often put in place for safety reasons, such as limited visibility, heavy traffic, or proximity to intersections. The prohibition serves to ensure smoother traffic flow, reduce the potential for accidents, and enhance the overall safety of the road environment.

While other options suggest varying degrees of permission or caution regarding U-turns, the sign clearly denotes an absolute ban on making such turns. Therefore, it is crucial for drivers to heed this signage to comply with traffic regulations and maintain safe driving practices.