Final answer:
The accessory nerve (CN XI) is a motor nerve that controls the muscles of the head, neck, and shoulders.
Step-by-step explanation:
The cranial nerve XI, also known as the accessory nerve, is a motor nerve. It is responsible for controlling the muscles of the head, neck, and shoulders. Unlike some other cranial nerves that have both sensory and motor functions, the accessory nerve is solely involved in motor functions.