An innovative physics professor conducts laboratory exercises in the college swimming pool. The professor places a submersible laser under water $)=(1\mathrm{.}3$ and aims the beam at a block of glass $)=(1\mathrm{.}5,$ which is also under water. At what angle of incidence will the reflected beam be totally polarized?

Multiple Choice

$41$

$61$

$39$

$49$