You have taken the right lane by mistake although you want to turn left. How are you allowed to proceed?

Your answer is correct because, according to German traffic rules, if you have accidentally taken the right lane but intend to turn left, you are allowed to continue straight ahead or turn right from that lane.

The markings and signs indicate that the right lane permits going straight or turning right only. Turning left from the right lane is not permitted because it would interfere with other traffic and violate lane usage rules.

This rule helps to prevent sudden lane changes and ensures smoother traffic flow and safety. If you want to turn left, you must be in the left lane before the intersection. Since you are in the right lane, the allowed movements are either going straight or turning right.