Complexes of the type $\left[\mathrm{M}{\left(\mathrm{a}\mathrm{a}\right)}_2{\mathrm{a}}_2\right]$ show geometrical or fac-mer isomerism. (where, aa = bidentate ligand and a is monodentate ligand.) Among the given, dichlorodiglycinato cobalt (III), I.e., $\left[\mathrm{C}\mathrm{o}\mathrm{C}{\mathrm{l}}_2{\left(\mathrm{g}\mathrm{l}\mathrm{y}\right)}_2\right]$ is such salt, so it will show fac and mer isomerism.