What is the primary function of the olfactory nerve (CN I)?

Correct answer is C). The olfactory nerve (CN I) is responsible for mediating the sense of smell. It transmits information about odors from the nasal cavity to the brain for interpretation and identification. A) Incorrect. The function described in option A pertains more to taste, which is primarily mediated by the taste buds on the tongue, and is associated with other cranial nerves (e.g., CN VII and CN IX). B) Incorrect. Facial muscle movements are controlled by the facial nerve (CN VII), not the olfactory nerve. D) Incorrect. Vision and eye movements are primarily controlled by CN II, III, IV and VI. The olfactory nerve has no direct involvement in vision or eye movements.