What is true in this situation?

Your answer is correct because driving on the restricted zone, which is marked by solid white diagonal lines, is prohibited. In German traffic rules, such road markings indicate an area where vehicles are not allowed to drive or stop. These zones serve to separate lanes, guide traffic flow, and increase safety.

Using the restricted zone to make a turn or to bypass traffic is not allowed. Even if there is a traffic jam, entering this area is prohibited to avoid confusion and accidents. Always stay within the marked lanes and use only the designated areas for turning or overtaking.

Remember, respecting these road markings helps maintain order and safety on the road.