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': 'Causes of localized hypopigmented macule or patch are all except \nSelect and explain. \nA. Vitiligo, B. Piebaldism, C. Pityr i as is alba, D. Freckle', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Freckles - multiple, ill-defined brown macules, which darken on sun exposure. Individual macules may show variation in skin color. All the other three condition produces localized hypopigmented macules or patch.', 'role': 'assistant'}]