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 Budd Chiari syndrome is: \nSelect and explain. \nA. Idiopathic, B. Valves in hepatic veins, C. Hepatocellular carcinoma, D. Thrombosis of hepatic veins', 'role': 'user'}, {'content': "Answer: D \nExplanation: Answer is D (Thrombosis of hepatic veins) Most common cause of Budd Chiari Syndrome is hepatic vein obstruction Its the common cause of hepatic vein obstruction causing Budd Chiari Syndrome is 'thrombosis of hepatic veins'.", 'role': 'assistant'}]