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': 'Which response is not seen in newborns as a measure of thermogenesis? \nSelect and explain. \nA. Shivering, B. Breakdown of brown fat, C. Universal flexion, D. Cutaneous vasoconstrictions', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ANSWER: (A) ShiveringREF: O.P Ghai 6th ed p. 151,152"Newborn cannot produce heat by shivering"Mechanisms for thermogenesis in new born are mainly due to rapid increase in circulating catecholamines due to cold stressLipolysis and re-esterification of brown fatPeripheral vasoconstrictionIncrease heart rate', 'role': 'assistant'}]