Which Maryland MVA fee statement is most accurate for Passenger endorsement applicants?

1. Maryland publishes CDL transaction fees such as a CDL learner's permit and skills retest fee, but not a separate Passenger-only knowledge-test fee on the CDL pages
2. Maryland publishes a fixed $500 Passenger-only written test fee
3. Maryland says all CDL passenger testing is free
4. Maryland publishes a separate Passenger fee based on the number of seats