The CFSE for octahedral $[CoC{l}_{2-6}{]}^{4-}$ is $18,000c{m}^{-1}.$ The CFSE for tetrahedral $[CoC{l}_4{]}^{2-6}$ will be

Select one:

a$.18,000c{m}^{-1}$

b$.20,000c{m}^{-1}$

C$.8,000c{m}^{-}$

d$.16,000c{m}^{-1}$