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 vitamin is required for transfer of 1-carbon unit ? \nSelect and explain. \nA. Vitamin A, B. Folic acid, C. Vitamin B12, D. Niacin', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Folic acid", 'role': 'assistant'}]