The answer is A. A warm and humid day with a wind moving in the same direction as the sound.
Sound waves travel through a medium such as solid, liquid, or gas. It travels faster when the molecules of its medium are closer together. This is the reason why it travels the slowest through dry air. When air is wet or humid, sound can travel faster because sound travels faster through water.
When sound waves pass through air, the most important factor that affects it is temperature. The higher the temperature, the faster the molecules vibrate. This allows sound waves to travel faster.
