What term describes the individual responsible for controlling ride operations?

The term that describes the individual responsible for controlling ride operations is "operator." This is a crucial role in any ride or attraction, as the operator ensures that all safety protocols are followed, monitors the operation of the ride, and manages the flow of guests. The operator is trained to respond to any issues that may arise during operation, providing safety and efficiency.

The other terms listed do not accurately represent this role. A participant refers to someone who is riding the attraction rather than managing it, while a rider is simply a guest using the ride. The restraint system is a safety feature used on rides to secure riders during operation but does not pertain to the individual controlling the ride. Thus, "operator" is the correct term for the person in charge of overseeing ride operations.