Which of the following change is observed when light travels from air to glass?

wavelength and speed of light only

The correct answer is Option (4) → wavelength and speed of light only

The speed of light decreases when it enters a denser medium like glass.

$v=\frac{c}{μ_0}$

The wavelength also decreases as,

$λ=\frac{v}{f}=\frac{c}{fμ_0}$