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: Surgery
[{'content': 'All of the following are common causes of haematemesis except - \nSelect and explain. \nA. Chronic peptic ulcer, B. Pernicious anemia, C. Esophageal varices, D. Carcinoma of stomach', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]