Answer;
A. lowering the humidity of the air.
Explanation;
-Waves travel through a medium: A medium is any substance or region through which a wave is transmitted. The speed of a wave is dependent on four factors: wavelength, frequency, medium, and temperature.
-Speed of a sound wave in air depends on factors such as temperature, humidity, and air pressure. The velocity of sound in gas is inversely proportional to the square root of density of the gas, with increase in temperature velocity of sound in a gas increases.
-Change in pressure has no effect on velocity of sound in a gas, so long as temperature remains constant. When humidity increases, there is an increase in the relative number of water molecules and hence a decrease in the molar mass and the speed of sound increases.
