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': 'Commonest type of vitiligo – \nSelect and explain. \nA. Vulgaris, B. Segmental, C. Acrofacial, D. Facial', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Most common type of vitiligo is vitiligo vulgaris.', 'role': 'assistant'}]