Light of wavelength $630\;\text{nm}$ in vacuum, falling normally on a biological specimen of thickness $10\;\mu\text{m}$, splits into two beams that are polarized at right angles. The refractive index of the tissue for the two polarizations are $1.32$ and $1.333$. When the two beams emerge, they are out of phase by
- $0.13^\circ$
- $74.3^\circ$
- $90.0^\circ$
- $128.6^\circ$