A ray of light from a denser medium strike a rarer medium at an angle of incidence i. The reflected and refracted rays make an angle of  ${90}^0$ with each other. The angles of  reflection and refraction are r and $r\text{'}$ . The critical angle is

• A

  ${\sin }^{-1}\left(\tan i\right)$

• B

  ${\sin }^{-1}\left(cot i\right)$

• C

  ${\sin }^{-1}\left(\tan r\text{'}\right)$

• D

  ${\tan }^{-1}\left(\sin i\right)$