Dynamic stretches are part of an effective warm-up because they can help build endurance for the activity. They also help in flexibility and range of motion in the human body.
A.) staying free of disease (physical)
B.) reflecting about yourself (mental)
C.) getting 8-10 hours of sleep each night (physical)
D.) engaging in 30-60 minutes of physical activity every day (physical)
Since B is a mental activity...
The answer = B. reflecting about yourself
Good Luck!