Which one of the following statements is true for sound waves propagating in air ?

Sound waves are classified as mechanical waves because they require a material medium (solid, liquid, or gas) to propagate. Unlike electromagnetic waves, sound cannot travel through a vacuum.

• Mechanical Nature: Sound travels by transferring energy through the vibration of particles in the medium.
• Longitudinal Nature: In air, sound waves propagate as longitudinal waves. This means the particles of the air vibrate back and forth parallel to the direction in which the wave travels, creating alternating regions of high pressure (compressions) and low pressure (rarefactions).

While sound can propagate as transverse waves in certain solids, in fluids like air and water, they are strictly longitudinal. Therefore, Option B is the correct statement.