This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Stomach & Duodenum, Subject name: Surgery
[{'content': 'Most common cancer to cause upper GI bleeding: \nSelect and explain. \nA. Cancer stomach, B. Cancer esophagus, C. Cancer liver, D. Metastasis to liver', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Cancer stomachRef: Sabiston 20th Edition, Page 1142Causes of upper GI bleeding:* Tumors form only 2% of bleeding source.* Of the various tumors: Most common tumor to cause upper GI bleed is cancer stomach.', 'role': 'assistant'}]