Which nerve primarily mediates the blink reflex?

The blink reflex is primarily mediated by the trigeminal nerve (Cranial Nerve V) and the facial nerve (Cranial Nerve VII). The trigeminal nerve is responsible for sensory input; it carries the sensory information from the cornea to the brain. When the cornea is stimulated, it initiates a reflex action. The motor response to this stimulus is mediated by the facial nerve, which innervates the muscles responsible for closing the eyelids. This coordination between the sensory input and motor response allows for the protective reflex of blinking.

The other cranial nerves listed do not play a role in mediating the blink reflex. For example, the oculomotor nerve is primarily involved in controlling eye movement and pupil constriction but does not participate in the sensory or motor components of the blink reflex. The hypoglossal nerve primarily controls tongue movement, and the trochlear nerve primarily facilitates movement of the superior oblique muscle of the eye. Thus, option B correctly identifies the nerves involved in the blink reflex.