Which statement about coupling and uncoupling is correct?

1. This choice is not supported by the Texas CDL handbook or FMCSA combination-vehicle standards.
2. High coupling occurs when the kingpin rides above or on top of the jaws instead of locking inside.
3. This statement confuses the tested combination-vehicle rule with an unrelated CDL topic.
4. This answer would create an unsafe coupling, braking, turning, or inspection habit.