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: Skin
Which of the following is wrong statements: 
Select and explain. 
A. Koilonychia in Vit B12 deficiency, B. Oncholysis in Psoriasis, C. Mees lines in Arsenic poisoning, D. Pterygium of nailis in Lichen Planus
A: Koilonychia in Vit B12 deficiency
Answer: A: Koilonychia in Vit B12 deficiency 
Explanation: Ans: A i.e. Koilonychia in Vit B12 deficiency. Koilonychia (Spoon nail) The nail is concave with raised edges. Seen in Iron Deficiency Anemia,Hypothyroidism,Lichen Planus.