How much initial Pennsylvania school-bus-specific instruction does PennDOT require for a new school bus endorsement applicant?

1. 20 hours total, including at least 14 classroom hours and 6 in-bus hours
2. 10 hours total, including 7 classroom hours and 3 in-bus hours
3. 6 classroom hours only
4. No specific instruction if the applicant already has a CDL