Which produces wave particles that move and displace one another

Is this the answer choices? Which produces wave particles that move and displace one another?

A) a radio
B) a guitar
C) a light bulb
D) a microwave oven

If so, the answer is B. A guitar generally produces sound waves that propagate when the strings are strummed. The strings are displaced through the vibrations caused by contact of the hand and the guitar. You will also notice the vibrations by looking closely to the string. Wave particles continuously collide with each other to make a sustaining or prolonging sound.

B. a circuit. i think