This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nutrition and health, Subject name: Social & Preventive Medicine
[{'content': 'Most commonly used for protein utilization - \nSelect and explain. \nA. NPU, B. Amino acid score, C. Biological value, D. Protein efficiency ratio', 'role': 'user'}, {'content': "Answer: A \nExplanation: -net protein utilisation: it is a product of digestibility coefficient and biological value divided by 100. - NPU= nitrogen retained by the body * 100/ nitrogen intake. Reference : Park's textbook of preventive and social medicine, 23rd edition, pg no:634 <\\p>", 'role': 'assistant'}]