The answer to this is D i think.
When you are in stress your body and mind are tense and your body and mind cannot concentrate or operate as it normally does, Resulting in many different downsides like not being able to exercise properly.
Let's say you enjoy swimming. One day you decide to swim alone. But it's a risky idea because you could drown and no one would be there to help you in time. So it's best to have others around incase you have an accident or need help.
