Based on spectrochemical studies, the correct increasing order of field strength of Ligands is

• A

  ${\mathrm{I}}^{-},{\mathrm{OH}}^{-},{\mathrm{NH}}_3,\mathrm{CO}$

• B

  ${\mathrm{Br}}^{-},{\mathrm{SCN}}^{-},\mathrm{CO},{\mathrm{CN}}^{-}$

• C

  ${\mathrm{OH}}^{-},{\mathrm{H}}_2\mathrm{O},{\mathrm{CN}}^{-},{\mathrm{NH}}_3$

• D

  ${\mathrm{H}}_2\mathrm{O},{\mathrm{NCS}}^{-},{\mathrm{F}}^{-},{\mathrm{OH}}^{-}$