Final answer:
Sound is not a transverse wave; it is a longitudinal wave, with variations in pressure moving in the direction of the wave. Light and radio are electromagnetic and transverse waves, with electric and magnetic fields oscillating perpendicular to the direction of propagation.
Step-by-step explanation:
The question you are asking about waves concerns whether they are transverse waves or longitudinal waves. Transverse waves involve a disturbance that moves perpendicular to the direction of the wave's travel. On the other hand, longitudinal waves involve disturbances that move in the same direction as the wave's travel. In your list, sound waves are the ones that are not transverse; they are longitudinal. Sound waves in air and water are composed of periodic variations in pressure that travel through the fluid medium.
In contrast, light waves and radio waves are types of electromagnetic waves, and they are inherently transverse waves. This means that the electric and magnetic fields oscillate perpendicular to the direction of wave propagation. Therefore, the correct answer to which one is not transverse is sound.