In Young's double slit experiment, a beam of light which is a mixture of three wavelengths ${\mathrm{\lambda }}_1,{\mathrm{\lambda }}_2$ and ${\mathrm{\lambda }}_2$, is incident normally on the on the plane of the slits. If third maximum of ${\lambda }_1$, fourth minimum of ${\mathrm{\lambda }}_2$ and second maximum of ${\mathrm{\lambda }}_3$ coincide on the screen, then ${\mathrm{\lambda }}_1:{\mathrm{\lambda }}_2:{\mathrm{\lambda }}_3$ is 

• A

  12 : 9 : 8

• B

  11 : 8 : 9

• C

  14 : 12 : 21

• D

  16 : 12 : 23