sound travels at maximum speed in A. steel B. water C. air D. vacuum

The speed of sound depends on the medium in which it is transported. Sound travels fastest through solids, slower through liquids and slowest through gases. the collision between particles is what mediates the propagation of sound. In fact, the sound is just a disturbance. This disturbance propagates better when the material it is traveling in is more "stiff" and has lower density. This is directly understood from the Newton-Laplace equation for the speed of sound. The speed of sound is the distance traveled per unit time by a sound wave as it propagates through an elastic medium. The speed of sound in air is about 343 meters per second.