Why may you not overtake in this situation?

In this situation, overtaking is not allowed for two key reasons: First, the view of oncoming traffic is blocked by a curve, making it impossible to ensure the road ahead is clear over the full overtaking distance. German law (§5 StVO) strictly prohibits overtaking when visibility is limited or the situation is unclear. Second, even if you are only a little faster than the cyclists, it would take a long time to complete the overtaking maneuver. A longer overtaking time increases risk, especially when you can’t see ahead clearly. Both reasons make overtaking unsafe here and are why both selected answers are correct. There is no no-overtaking sign present, so that is not a valid reason in this context. To solve similar questions, always check for visibility and make sure you can complete overtaking quickly and safely before doing so.