A California CLP holder has P and S endorsements and is driving a school bus with an accompanying CDL holder for training. Which passenger situation is allowed under the CLP restriction?

1. A full route of students because the CDL holder is present
2. Only the limited allowed passengers, such as the accompanying CDL holder, test examiner, other trainees, or federal/state auditors and inspectors
3. Any paying charter group as long as the bus is empty on the return trip
4. Students only if they are seated with seat belts