An Indiana applicant wants the S endorsement but has not passed the passenger endorsement skills test. What is the best interpretation of the requirement?

1. The applicant must qualify for the Passenger endorsement before satisfying the S endorsement requirements
2. The applicant can skip Passenger testing because school buses are not passenger vehicles
3. The applicant only needs a tank endorsement if the bus has a large fuel tank
4. The applicant may use a motorcycle skills test instead