What are the permitted driving directions according to the traffic signs in the following intersection?

- Straight and right.
- Straight and left.
- Correct answer: Straight only.
- Straight and a left U-turn.
Why this is the answer
The correct answer in the official bank: Straight only.
A round blue sign with a white arrow pointing up requires you to continue straight only. So at this intersection you may not turn right or left, and you may not make a U-turn. The only permitted driving direction is straight.