Chemistry - Coordination Chemistry Question with Solution | TestHub

Option (C) represents an octahedral complex of the type $[M{A}_3{B}_{2}C]$, specifically $[Co(CN{)}_3(N{H}_3{)}_{2}Cl{]}^{2-}$.

All possible geometrical isomers (both fac and mer forms) of this complex possess at least one plane of symmetry.

Because they contain a plane of symmetry, all its isomers are achiral (optically inactive).

Therefore, it cannot be resolved into enantiomeric 'd' and 'l' forms.