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': 'A child presents with a solitary white well-defined patch on his right thigh. Diagnosis is – \nSelect and explain. \nA. Piebaldism, B. Albinism, C. Nevus achromicus, D. Acral vitiligo', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Information is this question are :-\n\n\nLesion is on thigh\nUnilateral lesion (Isolated lesion on Right thigh)\n\n\nBoth these suggest Nevus achromicus, i.e. Nevus acromicus involves :-\n\n\nTrunk and proximal extremity (thigh in this question)\nLesion is unilateral\n\n\nAlso keep in mind that, though Nevus achromicus presents since birth, it may be missed at birth and the patient may\xa0present in childhood', 'role': 'assistant'}]