Correct answer choice is :
B) Knowing the frequencies of the original waves is useful in determining if the result will be discordant or harmonious
Step-by-step explanation:
The sound is generated when something vibrates. The vibrating body produces the mechanism around it to vibrate. Vibrations in the air are described as traveling longitudinal waves, which we can hear. Sound waves comprise of areas of high and low pressure named compressions and rarefactions.