Prática CDL combination vehicles

You are coupling to a loaded semitrailer. Before backing under it, you check the trailer height against your fifth wheel. Where should the trailer nose be?

• AHigh enough that the fifth wheel passes under with a gap.
• BLow enough that the tractor raises it slightly when backed under.
• CLevel with the top of the tractor frame rails.
• DExactly level with the fifth wheel plate so nothing lifts.