What is the forward distance of a full trailer (other than a pole trailer), the front axle of which is steered by a towbar?

• A. The distance between the mid-point of the rear and front axis of the trailer to the front of the vehicle or load
• B. The distance between the front axis of the trailer to the front of the vehicle or its load
• C. The distance between the rear axis of the trailer to the front of the vehicle or its load
• D. The distance from the rear axis to the front of the trailer (excluding any drawbars and/or the front axle set)