The correct answer is A. His diet should include foods such as eggs, nuts, and fish.
Step-by-step explanation:
The excerpt from the journal explains the importance of protein intake for athletes as this contributes to many body functions such as "enzyme production" or "growth and repair of tissues". In this context, athletes will need to have an appropriate protein intake, which is essential to growth muscles or repair them if there is a lesion. Moreover, this can be obtained through the intake of foods such as eggs, nuts, fish, grains, among others. In this context, the best decision is expressed in option A.