When system air pressure is routed into the trailer hold-off circuit,the parking brakes are:

A) 50% applied
B) 100% applied
C) 50% released
D) fully released

Hold-Off Circuit

A type of circuit used to delay or prevent the activation of part of a system until certain conditions are met.

System Air Pressure

The pressure of the air in a pneumatic system, which is critical for the operation of air-powered tools or vehicles.

Parking Brakes

A mechanism in vehicles designed to keep the vehicle stationary by mechanically locking the wheels, also known as a handbrake or emergency brake.