What is the statutory duty of a long-distance passenger coach driver regarding passenger seat belts before departing from a station?

1. Only ensure the front passenger seat belt is fastened, while leaving other passengers unmonitored
2. Broadcast a safety announcement reminding all passengers to fasten their seat belts, visually inspect that passengers have fastened them, and refuse to depart until all passengers are buckled (全员全程系安全带)
3. Seat belts are optional for passengers and the driver has no reminder obligation
4. Advise passengers to unfasten seat belts to sleep comfortably on the expressway