Light with a Wavelength of 589 Nm in a Vacuum

Multiple Choice

Light with a wavelength of 589 nm in a vacuum strikes the surface of an unknown liquid at an angle of 31.2° with respect to the normal to the surface. If the light travels at a speed of 1.97 × 10⁸ m/s through the liquid, what is the angle of refraction?

A) 19.9°
B) 26.1°
C) 34.2°
D) 39.3°
E) 51.9°