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': 'The reference protein is - \nSelect and explain. \nA. Fish, B. Egg, C. Rice, D. Lemon', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. is \'b\' i.e., Egg * Eggs are used in nutrition studies as a "reference protein" as eggs proteins are considered to be the best among food proteins because of their high biological value and digestibility.* So NPU is also high because it is the product of biological value and digestibility cofficient divided by 100.', 'role': 'assistant'}]