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': 'Which one of the following amino acid residue is carboxylated by Vitamin K? \nSelect and explain. \nA. Aspaate, B. Glutamate, C. Tryptophan, D. Tyrosine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Vitamin K is the cofactor for g-carboxylation of glutamate residues of protein to produce g-carboxy glutamate (gla). This process is known as Vitamin K epoxide cycle (as illustrated in the image below).', 'role': 'assistant'}]