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: Social & Preventive Medicine
[{'content': 'Which of the following has highest protein content: \nSelect and explain. \nA. Mutton, B. Soyabean, C. Egg, D. Milk', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Soyabean', 'role': 'assistant'}]