what does B represent?
![what does B represent class=](https://us-static.z-dn.net/files/d18/b5014e879f23486c40c32cd7be8c2a3d.png)
B is a trough.
A trough is the opposite of a crest, in that it occurs at the maximum negative displacement of a wave.
In this problem, A would be the crest, C would be the wavelength, and D would be the amplitude.
Hope this helps!! :)