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: Medicine
[{'content': 'A 40 year old female presents with a history of sudden onset of headache and nausea which passed off with rest and analgesics.Later she developed blurring of vision for a few days. On the day of admission she had developed third nerve palsy with neck rigidity. The temperature was 100°F.The most likely diagnosis is - \nSelect and explain. \nA. Acute attack of migraine, B. Viral encephalitis, C. Sub-arachnoid haemorrhage, D. Severe hypertension', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]