With respect to air critical angle in a medium for light of red colour [${\mathrm{\lambda }}_1$] is $\mathrm{\theta }.$ Other facts remaining same, critical angle for light of yellow colour [${\mathrm{\lambda }}_2$] will be 

• A

  $\mathrm{\theta }$

• B

  More than $\mathrm{\theta }$

• C

  Less than $\mathrm{\theta }$

• D

  $\frac{{\mathrm{\theta \lambda }}_1}{{\mathrm{\lambda }}_2}$