This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
[{'content': 'Aery involved in 3rd cranial nerve lesion? \nSelect and explain. \nA. Anterior communicating, B. Posterior communicating, C. Posterior cerebral, D. Anterior cerebral', 'role': 'user'}, {'content': "Answer: C \nExplanation: Harrison's textbook of internal medicine 17 th edition . *A third nerve past,paicularly when associated with pupillary dilatation ,loss of ipsilateral light reflex and focal pain above or behind the eye,may occur with an expanding aneurysm at the junction of posterior communicating aery and internal carotid aery .", 'role': 'assistant'}]