A Maryland CLP holder has a School Bus endorsement on the permit. Which passenger-carrying restriction applies?

1. The driver cannot carry school bus passengers except allowed auditors, inspectors, examiners, trainees, and the accompanying CDL holder
2. The driver may carry regular student passengers as long as the stop arm works
3. The driver may carry any passengers if the route is inside Maryland
4. The driver may carry students only when the bus is empty of cargo