What is true about the properties of a wave's amplitude?

The amplitude of a wave is a measure of the maximum displacement from its equilibrium position; it specifically represents the height of the wave from the center line (equilibrium position) to the crest (the highest point). In wave terminology, when describing amplitude, it is often described as the distance from the peak to the trough. Option B correctly identifies this relationship, making it the right choice.

Understanding this, it's important to recognize how amplitude relates to other wave properties. For example, amplitude is associated with the energy of the wave; higher amplitude typically means more energy. However, it does not influence the frequency, speed, or wavelength directly, as these properties are governed by other factors. Therefore, while the amplitude provides key insights into the intensity and energy of the wave, it does not determine frequency, speed, or wavelength, which involve different aspects of wave mechanics.