Which of the Following Is a Correct Statement About the Nature

Which of the following is a correct statement about the nature or behavior of sound?

A) Sound waves consist of compressions and rarefactions.
B) The frequency of a sound wave and its volume are the same.
C) Its speed is 186,000 miles/second (about 300,000 kilometers/second) .
D) Its speed at the surface of the earth does not vary with the temperature of the air.