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: Skin
[{'content': 'Following are signs of internal malignancy except: \nSelect and explain. \nA. Tuberous sclerosis, B. Acanthosis nigricans, C. Clubbing, D. None', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. None', 'role': 'assistant'}]