The crystal field spitting energy $\left({\mathrm{\Delta }}_{\text{o}}\right)$ of  

I)       ${\left[{\text{CoBr}}_{\text{6}}\right]}^{3-}$

II)     ${\left[{\text{CoF}}_{\text{6}}\right]}^{3-}$

III)    ${\left[\text{Co}{\left(\text{NCS}\right)}_{\text{6}}\right]}^{3-}$

IV)    ${\left[\text{Co}{\left(\text{CN}\right)}_{\text{6}}\right]}^{3-}$ 

is in the order 

• A

  II < IV < I< III          

• B

  I < II < III < IV

• C

  III < I < IV < II

• D

  IV < III < II < I