Answer: A
The further the yardstick falls, the slower the reaction time.
Explanation:
A yardstick test is a practice to measure up to one-yard high distance and time. A person holds the yardstick from above and the other person holds it with his/her two hands.
As the first holder releases the yardstick without any indication, the other holder runs to catch the yardstick as fast as possible. The time measurement would be 100% as it depends on the catcher's reaction time.