This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General surgery, Subject name: Surgery
[{'content': "The most common malignancy found in Marjolin's ulcer is \nSelect and explain. \nA. Basal cell carcinoma, B. Squamous sell carcinoma, C. Malignant fibrous histiocytoma, D. Neurotrophic malignant melanoma", 'role': 'user'}, {'content': 'Answer: B \nExplanation: Repeated question', 'role': 'assistant'}]