Which of the following prying/spreading tools is an example of a machine-powered rescue tool?

The hydraulic spreader is an example of a machine-powered rescue tool because it utilizes hydraulic pressure to amplify force, enabling firefighters to effectively spread apart materials such as vehicle doors or walls during rescue operations. This tool is specifically designed to manage heavy lifting and spreading tasks that would be too difficult to accomplish with manual tools.

In contrast, the other tools mentioned are manual or hand-operated. The Hux bar is a type of pry bar used for leverage, while the Rabbit tool and Kelly tool, although effective for certain prying tasks, rely on the physical strength of the operator and do not incorporate hydraulic or other powered mechanisms to assist in their operation. This distinction emphasizes the functional advantage that hydraulic spreaders provide in emergency rescue scenarios.