Answer:
B: wavelength
Explanation:
A wavelength (λ) is the distance between any two successive places where the shape of the wave repeats itself.
It can be the distance between
- two consecutive peaks
- two consecutive troughs
- three consecutive nodes (zero-crossings of the horizontal axis)
The wave is all these repeating units joined together in sequence.
A hertz is a unit of frequency, and a decibel is a measure of the loudness of a sound wave.
