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': 'Which of the following fat soluble vitamin has been  identified to function as a coenzyme? \nSelect and explain. \nA. Vitamin A, B. Vitamin K, C. Vitamin E, D. Vitamin D', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most of the water\xa0soluble\xa0vitamins\xa0exert\xa0the\xa0functions through their respective coenzymes while only one fat soluble vitamin (K) has been identified to function as a coenzyme.\nReference: Satyanarayana- Biochemistry, 3rd edition, pg-117', 'role': 'assistant'}]