What is one of the most important rules to remember about healthy eating?
a. eat 10 or more servings of fruit or vegetables daily.
b. eat a variety of foods, with moderation in everything.
c. eat only low-fat, low-salt foods while training.
d. eliminate snack foods and chocolate.

It is B. Eat a variety of foods, with moderation in everything.
Healthy eating is not excessive eating or eating very less to nothing at all, it's about eating the right amount and consuming proper proteins in order to keep your bodily functions at its best. Whole grain is recommended instead of refined grain. You also need to make a daily food planning schedule, proper eating timetable, without being obsessed by it. You need to intake just the right amount of ounces everyday, whether it is fruit, meat, or milk. You can even eat cheese, or fatty products, but you need to eat it right. Consult a nutritionist and identify how much calories you need everyday according to your age.