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': 'In patients with cirrhosis of the liver the site of obstruction in the portal system is in the - \nSelect and explain. \nA. Hepatic vein, B. Post sinusoidal, C. Extra hepatic portal vein, D. Sinusoids', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]