Final answer:
To test the integrity of rubber-insulated gloves, you should use method c) In a darkened area, shine a flashlight into the glove and check for light leakage.
Step-by-step explanation:
To test the integrity of rubber-insulated gloves, you should use method c) In a darkened area, shine a flashlight into the glove and check for light leakage. By shining a flashlight into the glove in a dark room, you can check for any holes or leaks in the insulation of the glove.