A human eye has three layers with refractive indices \(n{1}\,,\,n{2}\,,\) and \(n{3}\), where \(n{1}<n{2}\) and \(n{1}=n{3}\,.\) Which of the following properties of a light ray is the same in all layers?

W) Frequency only

X) Speed only

Y) Wavelength only

Z) Frequency and speed
W) FREQUENCY ONLY