8. Which of the following describes an electronic instrument?
a. It is a musical instrument that is sounded by being struck or scraped by a beater.
b. Musical instruments that produce sound from vibrating strings when the performer plays or sounds the strings in some manner.
c. Musical instrument that contains some type of resonator in which a column of air is set into vibration by the player blowing into a mouthpiece.
d. Musical instrument that produces sound using electronic circuitry.​