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
A patient has an invasive tumor in the cavernous sinus, presenting signs in the patient include all except 
Select and explain. 
A. A dilated pupil, B. A drooping eyelid, C. A weakness in screwing the eyes up tightly, D. A deviated eye looking down and laterally
C: A weakness in screwing the eyes up tightly
Answer: C: A weakness in screwing the eyes up tightly 
Explanation: Tight closing of eyes is a function of orbicularis oculi, which is supplied by facial nerve. This nerve doesn’t enter the cavernous sinus.