The statement a professional athlete who takes dance or gymnastics to improve their skills in their professional sport seems to be true. For instance, there are some ice skaters who take dance lessons. Football players taking dance lessons to help improve their footwork.
Answer:
Whole Grains
Explanation
Whole grains are healthier for most humans.
What isn't a function of proteins is storage and the transmission of heredity - a. For this job we have DNA and not proteins. For all the other things you've listed - help in fighting disease, control over the rate of reactions and regulation of cell processes and bone and muscle formations all are example of what proteins do.
I believe it is D! I hope this helps : )