Answer :
The "trailer air supply" control valve in the cab indeed controls the tractor protection valve, which is integral for managing air pressure to the trailer's brakes and for safety in case of separation or leaks. Therefore, option (A) true is the correct answer
The statement that the "trailer air supply" control valve in the cab controls the tractor protection valve is true. The trailer air supply control is specifically designed to manage the air pressure from the tractor to the trailer, and it essentially operates the tractor protection valve. This valve ensures that, in the event of a separation between the tractor and trailer or a significant air leak, the air supply to the trailer’s brake system is secured, thereby preventing the trailer brakes from releasing and causing a potential hazard.
