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': 'A 42-year-old company executive presents with sudden upper GI bleed (5 litres) of bright red blood, with no significant previous history. The diagnosis is- \nSelect and explain. \nA. Oesophageal varices, B. Duodenal ulcer, C. Gastritis, D. Gastric erosion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Both esophageal varices and duodenal ulcer are causes of massive upper GI bleed.\nAlthough it is difficult to reach a diagnosis by clinical history and physical examination alone, variceal bleed is less likely as there are no stigmata of chronic liver disease or portal hypertension.', 'role': 'assistant'}]