You are driving on this motorway. What is the right course of action?

Answer 1 is correct because on German motorways you must keep to the right (“Rechtsfahrgebot”). The left lane is mainly for overtaking. In the picture your lane is the left lane next to a lane closure/roadworks markings, while the right lane is open and usable. So once you are no longer actively overtaking and it’s safe, you should move back into the right-hand lane to keep traffic flowing and reduce the risk of tailgating and dangerous passing.

Answer 2 is wrong because the left lane is not a special “breakdown-only” lane. The breakdown lane is the hard shoulder (if present), and it may not be used for normal driving unless explicitly released by signs.

Answer 3 is wrong because staying in the left lane without a reason (no overtaking) violates the keep-right rule and can obstruct faster traffic coming from behind.

Rule of thumb: On the Autobahn, drive right whenever possible; use the left lane only for overtaking, then return to the right promptly when there’s a safe gap.