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
[{'content': 'Whitening of the nail plates may be due to deficiency of: March 2011 \nSelect and explain. \nA. Iron, B. Zinc, C. Albumin, D. Copper', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Albumin Leuconychia: Nails are white and are associated with hypoalbuminemia like cirrhosis of liver Nails and dermatology: Mees lines: Arsenic poisoning Oncholysis: Psoriasis Koilonychia: Iron deficiency anemia Koenens periungal fibroma: Tuberous sclerosis', 'role': 'assistant'}]