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 are features of Gummatous ulcer except - \nSelect and explain. \nA. Punched out edges, B. Syphylitic in nature, C. Wash leather slough, D. Erythematous base', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]