An athlete's diet should consist of
a. 30% carbohydrates, 10% fats, and 60% protein.
b. 30% carbohydrates, 30% fats, and 40% protein.
c. 60% carbohydrates, 30% fats, and 10% protein.
d. 10% carbohydrates, 30% fats, and 60% protein

The answer is C. 60 % Carbohydrates, 30 % fats, and 10 % protein

Athletes consumes a lot of energy. Which mean that they need their major source of energy should be fast to digest, which is Carbohydrates. Even though protein is really good to build muscle, it does not provide enough energy for athletes. 

Incase you would like to double check your answer - an athlete's diet should consist of B - 30% Carbohydrates, 30% Fats and 40% protein. The reason for this is that athletes need a higher amount of proteins but they also need suficient amont of the other two nutrients.