This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2018, Subject name: Medicine
[{'content': 'A 14 year old boy with difficulty in walking and behavioural disturbance, recovered from prolonged jaundice recently, has bluish pigmentation over lunula. The next investigation to be done: \nSelect and explain. \nA. Nail fold cappillaroscopy, B. Slit lamp examination, C. Biopsy of the pigmented area, D. Ankle-brachial pressure index', 'role': 'user'}, {'content': "Answer: B \nExplanation: Neurological involvement + Jaundice + Azure Nails (Bluish discoloration of nails) = Wilson's disease Dx: Slit lamp examination and 24 hrs urinary copper Rx: for Neurological feature - Tetrathiomolybdate", 'role': 'assistant'}]