This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Growth, Development, and Behavior, Subject name: Pediatrics
[{'content': 'What is this instrument used to measure? \nSelect and explain. \nA. Body mass index, B. Skin fold thickness, C. Upper segment: lower segment ratio, D. Mid arm circumference', 'role': 'user'}, {'content': "Answer: D \nExplanation: d. Mid arm circumferenceA measuring tape with cm markings (from 6to26cm) with 3 colored zones (red, yellow & green) is a Shakir's tape.", 'role': 'assistant'}]