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: Social & Preventive Medicine
[{'content': 'Commonest cause of stroke in our country- \nSelect and explain. \nA. Thrombosis, B. Embolism, C. Haemorrhage, D. Infarction', 'role': 'user'}, {'content': 'Answer: A \nExplanation: “Cerebral thrombosis is usually the most frequent form of stroke encountered in clinical studies, followed by haemorrhage”.', 'role': 'assistant'}]