The shut-off valves at the rear of the front trailer (first trailer) must be:

Open to supply air to the rear trailer.. Section 7.2: The valves at the rear of the front trailer must be OPEN to let air flow through the

The shut-off valves at the rear of the front trailer (first trailer) must be:

ANSWER BREAKDOWN
  • A. Incorrect. "Closed." is not correct. The valves at the rear of the front trailer must be OPEN to let air flow through the dolly to the second trailer.
  • B. Correct. The valves at the rear of the front trailer must be OPEN to let air flow through the dolly to the second trailer.
  • C. Incorrect. "Removed." is not correct. The valves at the rear of the front trailer must be OPEN to let air flow through the dolly to the second trailer.
  • D. Incorrect. "Partially open." is not correct. The valves at the rear of the front trailer must be OPEN to let air flow through the dolly to the second trailer.