Aperson can achieve optimum daily nutrition by
a. eating a variety of healthy foods.
b. excluding all fat from his or her diet.
c. eating large amounts of lean protein.
d. drinking at least six glasses of juice

Somebody who wants to achieve optimum daily nutrition will have to eat a variety of healthy foods (A) 

any of the other answers in this case also can contribute to a healthier nutritional lifestyle, however, the best among them is to eat a large variety of healthy foods, as recommended by WHO as well as different food experts and scientists.

Community maybe i’m not positive