Which sequence best matches the PennDOT Commercial Driver Manual procedure for coupling a tractor-semitrailer?

1. Connect air lines, then back under, then raise landing gear
2. Inspect fifth wheel, position tractor, back under, tug test, visual check, connect air and electrical, raise landing gear
3. Raise landing gear first, then back under, then tug test
4. Back under, raise landing gear, then connect air lines