This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Renal Regulation of Minerals, Subject name: Physiology
[{'content': '25-di hydroxy cholecalciferol is converted to 1,25-dihy- drocholecalciferol in: \nSelect and explain. \nA. Skin, B. Lung, C. Liver, D. Kidney', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) KidneyRef: Ganong 23rd ed. / 674', 'role': 'assistant'}]