I would say Frequency is how often you perform an activity, and Intensity is how hard/intensely you perform the activity.
Probably the last one. It's the least realistic way to make your body healthy. If you are going to do exercise and make yourself healthy, friends would be helpful in that process and exercising is definitely a good way to be healthy.
I guess it would be an example of self-control if your really tempted to cheat, and also honesty :)
