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 patient presented with thunder clap headache followed by unconsciousness with pregressive HI ranial nerve palsy. Likely diagnosis is - \nSelect and explain. \nA. Extradural hemorrhage, B. Aneurysmal subarachnoid hemorrhage, C. Basilar migraine, D. Cluster headache', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]