Under the PRC Road Traffic Safety Law and GB 7258, what is the mandatory requirement regarding seatbelt usage for all vehicle occupants inside a commercial taxi?

1. Only the driver needs to wear a seatbelt; passengers are exempt from wearing seatbelts
2. All occupants, including front-seat and rear-seat passengers, must fasten seatbelts while the vehicle is in motion, and the driver must actively remind passengers to buckle up
3. Seatbelts are only required on national holidays
4. Passengers may substitute holding hands for wearing seatbelts