Which statement correctly describes how trailer height matters when backing a converter dolly under the rear trailer during coupling?

49 CFR 383.115(a); AAMVA CDL Manual Section 7.2.1 "Coupling Twin Trailers," "Connect Converter Dolly to Rear Trailer" procedure, p. 7-2, Version July 2017

Getting trailer height wrong before backing under is one of the most common real-world coupling mistakes. It can damage the trailer nose or kingpin and leave the fifth wheel unable to lock, which is why the written test checks that you understand the height relationship, not just the general steps.