This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'A patient has an invasive tumor in the cavernous sinus, presenting signs in the patient include all except \nSelect and explain. \nA. A dilated pupil, B. A drooping eyelid, C. A weakness in screwing the eyes up tightly, D. A deviated eye looking down and laterally', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Tight closing of eyes is a function of orbicularis oculi, which is supplied by facial nerve. This nerve doesn’t enter the cavernous sinus.', 'role': 'assistant'}]