What can you expect now?

You chose 1 and 2, and that fits the typical Autobahn rule here.

Because you are in the left lane overtaking a line of slower trucks on the right, you should expect that the traffic situation ahead can change quickly: a vehicle in front of you in the left lane may be limited by the slower traffic and might brake, and vehicles from the right lane may want to pull out to overtake another truck. So you must be ready to brake rather than assume you can keep your speed.

Staying in the middle of your lane is also correct because it helps keep a safe lateral distance to large vehicles on your right and makes your driving predictable. On the Autobahn, the key rule of thumb while passing trucks is: keep a steady line, keep enough distance, and be prepared for sudden speed changes ahead.

Accelerating is not something you should “expect now” as the safe default, because during continuous overtaking you can’t assume the left lane will remain free; you only accelerate if you have clear space ahead and it’s safe, not as the likely next step.