You noticed that your friend Joey seems happier and more confident lately since he started being physically active. Joey's increased happiness and confidence is most likely a result of his: stretching every day
basketball four times a week
baling hay twice a week
the combination of these activities

I would say stretching everyday. That is what makes more sense to me, but I could be incorrect.

Explanation:

If a person wasn't doing much physical activity before, I doubt they could just get up and do things two - four times a week. But, I also don't know your material.

answer; teamwork;

this is true my friend.