According to the Road Transport Regulations of the PRC, how should a passenger bus driver handle suspicions that a boarding passenger is carrying flammable, explosive, or hazardous materials?

1. Ignore it as long as the passenger promises not to open the package during the journey
2. Politely request an inspection, strictly refuse carriage of prohibited dangerous goods, and report the matter to station security or the police if the passenger refuses compliance
3. Instruct the passenger to place the flammable items on the rear roof rack
4. Charge an extra freight surcharge and allow the passenger to board