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': "All of the following skin lesions are  premalignant except \nSelect and explain. \nA. Actinic keratosis, B. Oral leucoplakia, C. Bowen's disease, D. Acanthosis nigricans", 'role': 'user'}, {'content': 'Answer: D \nExplanation: Acanthosis nigricans is a skin lesion seen with underlying gastric malignancy, but it is not a precancerous lesion.', 'role': 'assistant'}]