This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition & Digestion, Subject name: Biochemistry
[{'content': 'Which Vitamin is required for carboxylation of clotting factors? \nSelect and explain. \nA. Vitamin A, B. Vitamin D, C. Vitamin E, D. Vitamin K', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D. Vitamin K(Ref: Harper 31/e page 529-533)Vitamin K is required for the post-translational carboxylation of glutamic acid (Gamma Carboxylation), which is necessary for calcium binding to g carboxylated proteins.', 'role': 'assistant'}]