What do these permanently illuminated signs mean?

Your choices 1 and 2 are correct.

On German motorways, these permanently illuminated lane-control signals above the lanes are mandatory, not just advice.

A green downward arrow above a lane means that lane is open and you may continue driving in it. That’s why lane 1 can be used normally.

A yellow diagonal arrow means you must leave that lane in the direction shown as soon as it is safe. It’s an instruction to change lanes, not a warning. Here it tells drivers in lane 2 to move to the right-hand lane.

Rule of thumb: Green arrow = lane open. Yellow diagonal arrow = change lane in that direction. Red X (even though it wasn’t one of the correct answers here) = lane closed; you must not drive in that lane.