What is the legal obligation of the coach driver regarding passenger seatbelt use before starting a journey in Switzerland?

1. The driver has zero duty to inform passengers about seatbelts
2. The driver must personally buckle every passenger's seatbelt by hand
3. The driver (or automated audiovisual announcement / pictograms) must inform passengers of the statutory requirement to wear seatbelts while the vehicle is in motion
4. The driver must lock all seatbelts permanently with a central key