Concept:The speed of sound depends on the properties of the medium through which it travels, not on the energy or amplitude of the wave.Explanation:The speed of sound is determined by factors such as temperature, wind direction, and the density of the material.Loudness is related to the amplitude of sound waves, which affects the intensity or energy carried by the wave.Changing the loudness of a sound does not change how quickly the sound wave moves through a medium.Therefore, loudness is the factor that does not affect the speed of sound.Answer:A. Loudness.