A light ray strikes a plastic block in air with angle of incidence $i$. The plastic has refractive index $n$. When the ray reaches X, it is refracted along the plastic-air boundary. Which equation is correct?
- A$\sin i = \frac{\sin 41^\circ}{n}$
- B$\sin i = \frac{n}{\sin 49^\circ}$
- C$\sin i = n\sin 41^\circ$
- D$\sin i = n\sin 49^\circ$