The nerve that is mixed among the options provided is the OCN III, also known as the Oculomotor nerve.
Explanation:
1. Vestibulocochlear nerve: This nerve is responsible for functions related to hearing and balance. It is purely sensory in nature, carrying information from the inner ear to the brain. Therefore, it is not a mixed nerve.
2. OCN III (Oculomotor nerve): This nerve is mixed, meaning it contains both sensory and motor fibers. It is responsible for controlling the majority of the eye muscles, including those that move the eye and control the size of the pupil in response to light.
3. OCN XII (Hypoglossal nerve): This nerve is mainly responsible for the movement of the tongue. It is a motor nerve and does not contain sensory fibers.
4. Optic nerve: This nerve is purely sensory and is responsible for transmitting visual information from the eye to the brain. It does not contain motor fibers and is not considered a mixed nerve.
Therefore, among the options provided, the OCN III (Oculomotor nerve) is the mixed nerve.
