Which of the following hair devices is permissible in volleyball?

The correct answer is unadorned flat barrettes no longer than 2 inches because this type of hair device meets the guidelines set by volleyball officiating rules. In volleyball, players are allowed to use hair accessories that do not pose a safety risk to themselves or other players. Unadorned flat barrettes are typically designed to hold hair in place without any protruding parts or embellishments that could potentially cause injury during play.

The requirement that they be no longer than 2 inches ensures that these barrettes do not interfere with the game or pose a potential hazard during fast-paced action. The acceptance of simple, functional hair accessories aligns with the safety measures implemented in volleyball to create a safe environment for all players.

In contrast, other options may include adornments or materials that could be considered unsafe or distracting during a match. For instance, a bobby pin with a soft plastic flower includes an embellishment that does not meet safety standards, and a headband made of hard plastic could create a risk of injury. Beads in the hair may also be deemed inappropriate as they can be seen as adornments that may hinder safety during play. Thus, selecting hair devices that prioritize safety while remaining functional is essential in volleyball officiating.