What do you have to be aware of when you see this traffic sign combination?

Your choices 1 and 2 are correct.

Answer 1 is correct because the warning sign indicates a level crossing ahead, and the additional striped board is a “countdown marker.” With three diagonal red stripes it means the crossing is still relatively far away, typically about 240 m before the level crossing (in steps of 80 m: 240 m, then 160 m, then 80 m as you get closer).

Answer 2 is correct because before level crossings you must not overtake. The rule of thumb is: do not start overtaking from the level-crossing warning sign until you have completely passed the level crossing, because you must be able to stop safely and you must not get stuck on or near the tracks.

Answer 3 would be wrong here because 120 m does not match this specific countdown board (that would correspond to a different stripe count/distance marker).