Answer: C
Explanation:
First, we must remember that amplitude is independent of or constant with respect to the frequency. This is because the amplitude represents how "loud" the wave is (in a sense), whereas the frequency is how high or low-pitched it is, so it cannot be A or B.
Recall the equation λ = v/f, where λ is the wavelength, v is the velocity, and f is the frequency of the wave. If the speeds of the waves are the same, then the frequency is inversely proportional to the wavelength, which means in this case that X has a shorter wavelength compared to y (because it has a higher frequency), which is C.
