A, because in all, stretching is to reduce muscle tightness and relax muscles. It also can be used as a warm up for sport activities, like a jog, or running a mile, etc.
It's also used a stretch warmup by P.E. Teachers sometimes. If you search up dynamic stretching it shows many stretches, and people do these all the time to prepare for exercise, or to loosen up tight muscles.
D)Risk behavior can harm your health