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: Pediatrics
[{'content': 'Which of the following is true about constitutional delay in growth ? \nSelect and explain. \nA. Neonates with constitutional delay show anomalies at birth, B. IGF–1 levels are low for chronological age, C. Bone age is normal, D. IGF–1 levels are low for bone age', 'role': 'user'}, {'content': 'Answer: B \nExplanation: In constitutional growth delay, IGF-1 levels tend to be low for chronological age but within the normal range for bone age.\nBirth weight and height are normal.\nBone age is less than chronological age.', 'role': 'assistant'}]