Final answer:
The correct answer is that the safety latch for the fifth wheel locking lever must be engaged for a proper coupling.
Step-by-step explanation:
The safety latch for the fifth wheel locking lever must be engaged for a coupling to be correct. Ensuring that the safety latch is properly engaged is a critical step in the coupling process for tractor-trailers. An engaged safety latch ensures that the fifth wheel locking mechanism is secure, preventing the trailer from detaching from the tractor during operation. This is a vital safety measure that drivers must check during pre-trip inspections and whenever the equipment is coupled.