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': 'The most common cause of short stature is – \nSelect and explain. \nA. Constitutional, B. Systemic diseases, C. Hypothyroidism, D. Growth hormone deficiency', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Constitutional delay in growth\n\nThis is significant cause of short stature in mid childhood period but the ultimate height is normal.\nTheir birth weight and height are normal.\nStrong family history of parents having short stature in childhood with delay in onset of puberty is usually present.\nThe average growth velocity is normal and ultimate growth potential is adequate.\nThe bone age is less than chronological age.\nUpper segment and lower segement ratio is normal.\nGrowth hormone and gonadotropin level after puberty are within normal range.\nNo treatment is required. The parents need to be reasured.', 'role': 'assistant'}]