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': 'Most common cause of subarachnoid hemorrhage is - \nSelect and explain. \nA. Hypertension, B. Berry aneurysm, C. Intracranial tumors, D. Arterio-venous malformations (AVM)', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]