What do you have to be aware of in this situation?

You answered correctly because these signs warn that the left lane will become narrower in 200 meters. This information is important especially for vehicles that are wider than usual, including their exterior mirrors. According to German traffic rules, if your vehicle (including mirrors) is wider than the allowed width for that lane, you need to be particularly cautious when the lane narrows to avoid accidents or violations.

The signs are not just indicating that the lane narrows temporarily, but specifically providing a distance (200 m) to this change. This helps drivers prepare in advance, for example by adjusting their position or speed safely.

The third option about the lane narrowing "for a distance of 200 m" is not correct here because the signs specify the narrowing will start in 200 m, but do not indicate how long the narrowing lasts.

In future similar situations, always check the signs carefully for both the distance to the road change and any vehicle width restrictions so you can adjust appropriately.