What is the meaning of the following traffic signs?

- No left turn for public vehicles only.
- Correct answer: A turn at the nearest left or nearest right turn is not permitted.
- No left or U-turn.
- No left U-turn only.
Why this is the answer
The correct answer in the official bank: A turn at the nearest left or nearest right turn is not permitted.
Each sign shows a black arrow turning in one direction, crossed by a red diagonal stripe. The left sign prohibits turning left at the nearest turn, and the right sign prohibits turning right at the nearest turn. The ban applies to all vehicles, not only public vehicles. U-turns have their own separate sign.