This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
[{'content': 'Hydroxylation of proline in collagen requires which of the following: \nSelect and explain. \nA. Vitamin C, B. Fe2++, C. a-ketoglutarate, D. All of the above', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. D. All of the aboveProline and Lysine are hydroxylated to form hydroxyl proline and hydroxyl lysine in the presence of enzyme hydroxylase and requires Fe2++' ascorbic acid (Vitamin C), oxygen and a- ketoglutarate.", 'role': 'assistant'}]