Which statement best illustrates vibrational motion?

a. a racecar driver speeding around a track
b. a model walking down a runway
c. a cello playing music at a concert
d. a ballerina twirling in place

c.a cello playing music at a concert

Explanation:

Vibration motion is produced when the strings of a cello are plucked by a musician. Vibration in a string produces a wave, and the vibrating string produces a sound of a certain frequency. Most often we see the tension of a string gets adjusted, and thus help to create a sound or music of a definite frequency.

it is b that is the answer.