A CDL holder has a CLP with passenger and school bus endorsement authority and an experienced CDL holder is supervising. What passenger-carrying rule still applies?

1. The CLP holder may not operate the CMV while carrying passengers
2. The CLP holder may carry pupils if the supervisor sits in the front seat
3. The CLP holder may carry passengers only on school grounds
4. The CLP holder may carry passengers if the bus is empty on the return trip