A beam of light propagating in medium A with index of refraction n(A) passes across an interface into medium B with index of refraction n(B). If v(A) and v(B) are the speeds of light in A and B respectively. Then which of the following is true ?

• A

  $\mathrm{v}\left(\mathrm{A}\right) > \mathrm{v}\left(\mathrm{B}\right)\text{ and }\mathrm{n}\left(\mathrm{A}\right) > \mathrm{n}\left(\mathrm{B}\right)$

• B

  $\mathrm{v}\left(\mathrm{A}\right) > \mathrm{v}\left(\mathrm{B}\right)\text{ and }\mathrm{n}\left(\mathrm{A}\right) < \mathrm{n}\left(\mathrm{B}\right)$

• C

  $\mathrm{v}\left(\mathrm{A}\right) < \mathrm{v}\left(\mathrm{B}\right)\text{ and }\mathrm{n}\left(\mathrm{A}\right) > \mathrm{n}\left(\mathrm{B}\right)$

• D

  $\mathrm{v}\left(\mathrm{A}\right) < \mathrm{v}\left(\mathrm{B}\right)\text{ and }\mathrm{n}\left(\mathrm{A}\right) < \mathrm{n}\left(\mathrm{B}\right)$