What does a "no U-turn" sign indicate?

A "no U-turn" sign clearly indicates that making a U-turn is prohibited at that particular intersection. This restriction is implemented for various reasons, such as ensuring traffic safety, minimizing congestion, and maintaining the flow of vehicles. When drivers see this sign, they must understand that turning around in the opposite direction at that location is not legally allowed, and they should find an alternative route to turn around if necessary.

The other options imply varying degrees of permission or conditional allowances for U-turns, which contradict the clear and unequivocal directive provided by the "no U-turn" sign. The goal of such signage is to simplify driving choices and enhance road safety by minimizing confusion about what is permitted.