Respuesta :
Answer:
D. The distance between two identical points of a wave
Explanation:
Wavelength is the the distance between successive crests of a wave, especially points in a sound wave or electromagnetic wave.
You can look at the picture to show wavelength.
Hope this helps!!
- Kay

it is D, wavelength is from trough to trough or peak to peak, since D means identical points of a wave, this means it will definitely match the points on the peak of the first wave and the second wave, which is defined as wavelength