According to the Provisions on the Administration of Road Transport of Dangerous Goods (the Provisions on the Administration of Road Dangerous Goods Transport (MOT Order 2013 No. 2, as amended)), what is the strict rule regarding carrying unauthorized passengers in dangerous goods vehicles?

1. It is strictly forbidden to carry any unauthorized personnel or passengers unrelated to transport operations in the vehicle cab
2. Up to 10 paying hitchhikers may ride on the rear tanker ladder for short distances
3. Passengers are permitted if they agree to wear safety goggles
4. Any passenger carrying an open flame matchbox may ride for free