If the emergency line (Red) comes apart while you are driving:

The trailer emergency brakes will come on.. Section 6.2: If the emergency line loses pressure, the trailer emergency brakes will apply

If the emergency line (Red) comes apart while you are driving:

ANSWER BREAKDOWN
  • A. Incorrect. "Nothing happens." is not correct. If the emergency line loses pressure, the trailer emergency brakes will apply automatically.
  • B. Correct. If the emergency line loses pressure, the trailer emergency brakes will apply automatically.
  • C. Incorrect. "You lose steering." is not correct. If the emergency line loses pressure, the trailer emergency brakes will apply automatically.
  • D. Incorrect. "The service brakes work better." is not correct. If the emergency line loses pressure, the trailer emergency brakes will apply automatically.