Final answer:
Motor vehicles must be in an operable condition when working within an off-highway job site for safety and efficiency. This ensures that all systems are functioning properly to prevent accidents.
Step-by-step explanation:
The statement that motor vehicles operating within an off-highway job site need to be in an operable condition is true. For the safety of all personnel and to ensure the efficiency of operations, it's imperative that all equipment, including motor vehicles, are maintained in good working order. This is especially critical in job sites that may have unique hazards or require vehicles to handle rough terrain and heavy loads. An operable condition means that all necessary systems, such as brakes, lights, and warning devices, must function properly to avoid accidents and disruptions on the job site.