Which cranial nerve is responsible for hearing and balance?

The cranial nerve responsible for hearing and balance is the acoustic nerve, also known as the vestibulocochlear nerve. This nerve is crucial for the auditory system and plays a vital role in our ability to perceive sound and maintain equilibrium. It comprises two components: the cochlear part, which is involved in hearing, and the vestibular part, which is responsible for balance. Proper functioning of the acoustic nerve is essential for these sensory duties, making it central to auditory and vestibular systems.

Other options listed pertain to different functions and systems in the body. The glossopharyngeal nerve is primarily involved in taste and swallowing, while the spinal accessory nerve is associated with movements of the shoulder and neck. The optic nerve is solely responsible for vision. Therefore, the acoustic nerve's specific role in both hearing and balance clearly distinguishes it from these other cranial nerves.