They are basically the same thing
For substantial health benefits, adults should do at least 150 minutes (2 hours and 30 minutes) a week of moderate-intensity, or 75 minutes (1 hour and 15 minutes) a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity.
The mastery hypothesis: the mere fact that they are exercising makes patients feel like they have achieved something, cheering them up much as learning a new hobby or achieving a certain goal might cheer them up.
That sounds like B to me.
I would think more relaxed would be the best option since exercise can help with stress.
Mammogram is the most common diagnostic test for breast cancer.