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': 'Wrong statement is – \nSelect and explain. \nA. Mees line in arsenic poisoning, B. Pterygium of nails in Lichen planus, C. Onycholysis in Psoriasis, D. Koilonychia in Megaloblastic Anemia (B12 def)', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Koilonychia is seen in iron deficiency anemia (not in megaloblastic anemia).\nMees line is seen in Arsenic poisoning.\nPterygium is diagnostic for lichen planus.\nPsoriasis can cause onycholysis', 'role': 'assistant'}]