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: Physiology
[{'content': '25-di hydroxy cholecalciferol is converted to 1,25-dishy- drocholecalciferol in: \nSelect and explain. \nA. Skin, B. Kidney, C. Lung, D. Liver', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]