Final answer:
The example of a longitudinal wave among the given options is sound. Light and radio waves are examples of transverse waves, while ocean waves have components of both longitudinal and transverse waves.
Step-by-step explanation:
An example of a longitudinal wave among the options provided is sound. Longitudinal waves are characterized by the medium oscillating parallel to the direction of the wave propagation. This is true for sound waves, where disturbances are periodic variations in pressure that transmit through fluids, such as air and water.
Light waves and ocean waves are not longitudinal; light is an example of a transverse wave where the electromagnetic fields oscillate perpendicular to the direction of wave propagation. Radio waves, like light, are also transverse electromagnetic waves. Ocean waves are a combination of both transverse and longitudinal motions, although the simplified version we often see shows primarily transverse motion.