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: Social & Preventive Medicine
[{'content': 'Body content of thiamine is: \nSelect and explain. \nA. 5 g, B. 6 g, C. 20 g, D. 30 g', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Body content of thiamine is placed at 30 mg and if more than this is ingested, it is merely lost in urine. Ref: Park 22nd edition, page 572', 'role': 'assistant'}]