9. What happens to the particles of a medium when the temperature is high?
A. The particles of a medium move faster and collide more frequently therefore, the faster the speed of sounds
materials
B. The particles of a medium move faster and collide less therefore, the slower the speed of sound in the materia
C. The particles of a medium move slower and collide less therefore, the faster the speed of sound in the materia
D. The particles of a medium are stationary therefore, there is no speed of sound observed​