This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Newborn Infant - Physical Examination, Subject name: Pediatrics
[{'content': '"Microsomia" is defined as: \nSelect and explain. \nA. Birth weight below 90th percentile, B. Birth weight below 10th percentile, C. Birth weight below 20th percentile, D. Birth weight below 5th percentile', 'role': 'user'}, {'content': "Answer: B \nExplanation: b. Birth weight below 10th percentile(Ref: Nelson's 20/e p 789-791, Ghai 8/e p 124-125)Microsomia is another name for a small for date (SFD) or small for gestational age (SGA) baby.SFD baby is a baby whose birth weight is less than 10th centile of expected according to the gestational age.", 'role': 'assistant'}]