This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid, Electrolyte, Subject name: Pediatrics
[{'content': 'Total body water at bih is:- \nSelect and explain. \nA. 90%, B. 75%, C. 60%, D. 30%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Total body water (TBW) constitutes: 90% of body weight in early fetal life 75% of body weight at bih 60% by the end of 1styear & remains so till pubey', 'role': 'assistant'}]