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': 'Which cancer develops in chronic ulcer \nSelect and explain. \nA. Malignant melanoma, B. Basal cell CA, C. Squamous cell CA, D. Kaposi sarcoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Answer- C. Squamous cell CAChronic ulcer can cause squamous cell carcinoma.', 'role': 'assistant'}]