John's grandfather clock has a pendulum that keeps the seconds. What does this graph say about the observed pattern of motion?
A) The pendulum swings with a constant velocity.
B) The vacillating periodic motion changes sign.
C) The pendulum displays a constant acceleration.
D) The oscilations show a variable rate of motion.
![Johns grandfather clock has a pendulum that keeps the seconds What does this graph say about the observed pattern of motionA The pendulum swings with a constan class=](https://us-static.z-dn.net/files/df6/de3f5bb050e4366cc32ebbeeba3f4afc.png)