Final answer:
The solution is a Positioning system, which allows workers to be hands-free while securing them in case of contact loss with their support.
Step-by-step explanation:
The correct answer to the student's question is C) Positioning system. This type of system allows a worker to maintain their position while keeping their hands free and provides a limited fall arrest function when the worker loses contact with the structure they are working on, such as when a worker's spurs lose contact with a utility pole they are climbing. In contrast, a restraint system prevents a fall from occurring by keeping the worker from reaching an area where a fall could occur, a fall arrest system is designed to stop a fall that's already in progress, and a suspension system supports a worker who is suspended in a harness, typically for tasks that require the worker to be elevated for an extended period.