This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neoplasia, Subject name: Surgery
[{'content': "Not a premalignant ulcer: \nSelect and explain. \nA. Bazin's ulcer, B. Pagets disease of nipple, C. Marjolin's ulcer, D. Lupus vulgaris", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans: a (Bazin's ulcer)Ref: Bailey & Love, 24th ed, p. 208 for 'c' p. 1837 for 'b'& 23rd ed, p. 148 for 'c' p. 181 for 'd' S. Das surgery, 3rd ed, p. 129 for 'a' p. 130 for 4d'", 'role': 'assistant'}]