I believe that it would be A.It's a natural part of our everyday lives, even though some stress can be beneficial but not in large amounts
The term duration refers to C. how long a workout or exercise lasts.
Explanation:
The definition of duration is "the time during which something continues." C is the only answer having to do with the time the workout continues at.
Living by your personal values sounds easy—at least in theory. Your values, after all, are simply the things that are important to you in life, so it should be natural to live by them.