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
Protein efficiency ratio is – 
Select and explain. 
A. Gain in weight per unit of protein consumed, B. Product of digestibility coefficient and biological value divided by 100, C. Percentage of nitrogen retained out of the nitrogen absorbed, D. Percentage of protein absorbed after digestion
A: Gain in weight per unit of protein consumed
Answer: A: Gain in weight per unit of protein consumed 
Explanation: Protein Efficiency ratio is one of several methods which may be employed for evaluation of quality of protein:
Protein efficiency ratio = Weight increase (in grams) / Gm. of protein consumed
Protein efficiency ratio measures the influence on the weight increase in weaning animals.