Where is it forbidden to stop?

Stopping is not allowed in front of fire service access roads because these areas must always remain clear for emergency vehicles. Blocking a fire service access road can delay urgent rescue or firefighting operations, which is why German traffic rules strictly prohibit stopping there, even for a short time. For the other options: stopping is not generally banned on all one-way roads unless other specific rules apply, and in non-parking zones, you are only prohibited from parking long-term, but brief stops are usually allowed unless a stop is explicitly forbidden. So, only answer 1 is correct for this question.