How should you turn left from a road on which the following sign is placed?

- You should start turning from the central lane.
- Correct answer: From the left side, unless otherwise signposted.
- You should turn from the far right lane.
- It is forbidden to turn left. You are only allowed to drive forward.
Why this is the answer
The correct answer in the official bank: From the left side, unless otherwise signposted.
The sign marks a one-way road, on which all vehicles travel in the same direction. On such a road you turn left from the left side of the road, just as you turn right from the right side, unless marked otherwise. So the left turn does not start from the far right lane or from the central lane.