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
Which of the following has highest protein content: 
Select and explain. 
A. Mutton, B. Soyabean, C. Egg, D. Milk
B: Soyabean
Answer: B: Soyabean 
Explanation: Soyabean