A. 1.0 cm
Step-by-step explanation
Wavelength refers to the length of a wave from one peak to the next,The wavelength is measured from peak to peak. Wavelength is directly related to the frequency of a given wave form
so
we need to find the distance from peak to peak
to do that, subtract the x components of the peaks , so

therefore, the answer i
A. 1.0 cm
I hope this helps you