These narrow vertical curtains are used as masking. a Arms b Legs c Cycs d Flys

The correct answer is d) Flys.Flys are narrow vertical curtains used as masking in theater and stage settings. They are typically used to mask the lighting equipment and other backstage areas from the audience's view. Flys are attached to a system of ropes and pulleys, allowing them to be easily opened and closed as needed during a performance.