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 child presents with massive hemetemesis and systemic hypotension (He has no fever or other significant history) Examination reveal massive splenomegaly but no hepatomegaly) Likely diagnosis is - \nSelect and explain. \nA. Hepatocellular carcinoma, B. Bleeding duodenal ulcer, C. Extrahepatic portal venous obstruction, D. Non-cirrhotic portal fibrosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]