$A$ plane wavefront is incident on a water surface at an angle of incidence $60^{\circ}$. It then gets refracted at an angle of $45^{\circ}$. The ratio of the width of the incident wavefront to that of the refracted wavefront is $\left[\sin \frac{\pi}{4}=\cos \frac{\pi}{4}=\frac{1}{\sqrt{2}}, \sin 60^{\circ}=\frac{\sqrt{3}}{2}, \cos 60^{\circ}=\frac{1}{2}\right]$

• A
  $\frac{\sqrt{3}}{2}$
• B
  $\frac{\sqrt{6}}{2}$
• C
  $\frac{1}{\sqrt{2}}$
• D
  $\sqrt{2}$