Which of the following is a good example of behavior modification for changing snacking behavior?

AWhen I want a snack, I'll take a 20-minute walk, then reevaluate whether or not I still want it.

BWhen I want a snack, I'll take only half of what I really wanted.

(C.) I won't purchase any extra food.

DI won't eat dessert so I can have snacks throughout the day.