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 the highest protein energy ratio? 
Select and explain. 
A. Milk, B. Pulses, C. Potato, D. Fish
D: Fish
Answer: D: Fish 
Explanation: Food item Protein energy ratio Fish 80% Milk 20% Pulses 24% Rice 8% Potato 6% Ref: Park 21st edition, page 586.