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 food is having the highest protein content when compared to others? 
Select and explain. 
A. Mutton, B. Soya bean, C. Egg, D. Milk
B: Soya bean
Answer: B: Soya bean 
Explanation: Protein value of some common foods (g/100 g): Mutton 21.4 Fish 19.5 Egg (hen) 13.3 Liver goat 20 Cow's milk 3.2 Soya bean 43.2 Bengal gram 17.1 Ref: Textbook of Preventive and Social Medicine by K Park, 19th edition, Page 498.