Which question would lead to the BEST topic for a report on eating healthy foods?

Responses
A How often should I exercise?How often should I exercise?
B Can I have third helpings of everything?Can I have third helpings of everything?
C What kind of foods are considered junk foods?What kind of foods are considered junk foods?
D How many hours of sleep should I get each night?How many hours of sleep should I get each night?

C What kind of foods are considered junk foods?