What makes the yardstick test a direct measurement of reaction time? a. the further the yardstick falls, the slower the reaction time. b. yardsticks have numerical markings for length. c. yardsticks are designed to measure reaction time. d. all of the above select the best answer from the choices provided.

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.  

your answer will be c. sorry if im wrong: )