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 are signs of internal malignancy except – \nSelect and explain. \nA. Acanthosis nigricans & annular erythema, B. Bullous pyoderma & migratory necrotizing erythema, C. Granuloma annulare, D. Erythema annulare', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]