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: Dental
[{'content': 'Acanthosis Nigricans in old pt. Usually indicate – \nSelect and explain. \nA. Skin disorder, B. Malignancy, C. Senile brain, D. Usually found in negro', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]