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: Biochemistry
[{'content': 'The site at which 1,25 hydroxylation of Vitamin-D takes place in the kidneys is: \nSelect and explain. \nA. Collecting ducts, B. Glomerulus, C. Proximal convoluted tubules, D. Distal convoluted tubules', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Proximal convoluted tubules', 'role': 'assistant'}]