Final answer:
Exercises requiring quick changes of direction can improve your reaction time.
Step-by-step explanation:
The most true statement about reaction time is B. Exercises requiring quick changes of direction can improve your reaction time. Reaction time is the time it takes for you to respond to a stimulus, such as catching a dropped ruler or hitting the brake pedal in a car. By doing exercises that challenge your ability to quickly change direction, such as agility drills or sports like basketball or soccer, you can improve your reaction time.