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: Physiology
[{'content': 'FIGLU excretion in the urine, is an index of the deficiency of: \nSelect and explain. \nA. Thiamine, B. Niacin, C. Pyridoxine, D. Folate', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Folate', 'role': 'assistant'}]