Answer:
A. An infant is the correct answer.
Step-by-step explanation:
An infant should have the highest concentration of protein in his or her diet.
Protein is made of amino acids and it is the most necessary nutrients which our body requires to function properly.
Infants required a higher concentration of protein because they are in the growing stage so for the proper growth and also they need higher protein for the proper growth of tissues and the organs.
It would find that extra requirement for protein would be highest as rapid growth example throughout infancy.
That is the reason it has been believed that the relative level protein requirements of growing children are more important than adults.