The amplitude of a mechanical wave shows option D.) “how much energy the wave is transporting.”
When looking at amplitude visually, we will find that it’s identified by its displacement from the equilibrium point of the wave (the middle).
Options A, B, and C are all incorrect because they refer to the wave’s “frequency,” which is how much time it takes for a wave to pass a given point.
Answer Recap: The amplitude of a mechanical wave shows [Option D].