Electromagnetic waves of frequency $1.2\times {10}^{15}Hz$ enter into water and subsequently into glass from Vacuum. Which of the following graphs correctly represent the variation of frequency $\text{'}f\text{'}$ with medium? ( given that indices of refraction for water and glass are $\frac{4}{3}$ and $\frac{3}{2}$ respectively)

• A

   

  

• B

   

  

• C

   

  

• D