Which statement about coupling and uncoupling is correct?

1. This answer would create an unsafe coupling, braking, turning, or inspection habit.
2. This choice is not supported by the Texas CDL handbook or FMCSA combination-vehicle standards.
3. Disconnected air and electrical lines should be secured to protect them from dirt, moisture, and damage.
4. This statement confuses the tested combination-vehicle rule with an unrelated CDL topic.