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': 'Malignant transformation is commonly seen in ? \nSelect and explain. \nA. Stomal ulcer, B. Gastric ulcer, C. Chronic Duodenal ulcer, D. None', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. is None Earlier it was thought the malignant transformation occurs in chronic gastric ulcer but recent evidences suggest that it is not so. Those found to be malignant are malignant from the very beginning and are mistakenly labelled as benign due to inadequate biopsy.', 'role': 'assistant'}]