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: Medicine
[{'content': 'Nail and half nail sign, seen in uremia is - \nSelect and explain. \nA. Due to melanin deposition, B. Increased capillary density at the distal half of nails, C. Hypoproteinemia, D. Circulating toxin', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]