part a consider the transverse wave seen here. identify the appropriate wave part that also helps us to…

Brief Explanations:

The frequency of a wave is related to its wavelength through the wave - speed formula $v = f\lambda$, where $v$ is the wave speed, $f$ is the frequency, and $\lambda$ is the wavelength. Crests and troughs are points on the wave, and amplitude is the maximum displacement from the equilibrium position. Wavelength is the key wave - part for determining frequency.

Answer:

C. wavelength