This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastro Intestinal System, Subject name: Pediatrics
[{'content': 'A 12-year-old boy presents with hematemesis, melaena and mild splenomegaly. There is no obvious jaundice or ascites. The most likely diagnosis is: \nSelect and explain. \nA. EHPVO, B. NCPF, C. Cirrhosis, D. Malaria with DIC', 'role': 'user'}, {'content': "Answer: A \nExplanation: A. EHPVO(Ref: Nelson's 20/e p 1972)The given history is suggestive of portal hypertensionExtrahepatic portal vein obstruction is an important cause of portal hypertension in childhood.The obstruction can occur at any level of the portal vein.", 'role': 'assistant'}]