Final answer:
An inspector is required to operate any shut-off valves of the plumbing system.
Step-by-step explanation:
An inspector is required to operate any shut-off valves of the plumbing system. Shut-off valves are used to control the flow of water or other fluids in a plumbing system. They allow the inspector to isolate specific sections of the plumbing system for testing or maintenance purposes. For example, by closing a shut-off valve, the inspector can stop the flow of water to a certain area and check for leaks or perform repairs.