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
Which nerve is compressed by aneurysm of posterior communicating artery in circle of willis 
Select and explain. 
A. Hypophysis cerebri, B. Trochlear nerve, C. Oculomotor nerve, D. Optic nerve
C: Oculomotor nerve
Answer: C: Oculomotor nerve 
Explanation: None