Which cranial nerve is primarily involved in motor control of the tongue?

The cranial nerve that is primarily involved in the motor control of the tongue is the hypoglossal nerve, also known as cranial nerve twelve. This nerve is responsible for innervating the muscles of the tongue, which play a crucial role in actions like speaking, swallowing, and manipulating food during chewing. The hypoglossal nerve's motor functions allow for precise and coordinated movements of the tongue, crucial for effective oral communication and digestion.

In contrast, the other cranial nerves listed do not participate in the motor control of the tongue. The vestibulocochlear nerve is primarily involved in hearing and balance, the spinal accessory nerve primarily innervates the trapezius and sternocleidomastoid muscles for shoulder and neck movement, and the vagus nerve has a diverse set of functions, including parasympathetic control of the heart and digestive tract but does not control tongue movements. Thus, the hypoglossal nerve stands out as the primary nerve for motor control of the tongue.