Review Question - QID 214615

A 65-year-old man presents to a neurologist for increased volume in his left ear that began 1 week ago. The patient has no significant past medical history and has not had any prior audiological issues. His partner notes that the patient has also been adding more salt to his food than before. On physical examination, the patient has left eyebrow sagging with an absence of the left nasolabial fold. Which cranial nerve is most likely involved in this patient’s condition?