Which of the following molecules/ions can exhibit isomerism?

A) $\mathrm{Tetrahedral} {\mathrm{NiCl}}_2{{\mathrm{Br}}_2}^{2-}$
B) $\mathrm{Squareplanar} \mathrm{Pt}{\left({\mathrm{NH}}_3\right)}_2{\mathrm{Cl}}_2$
C) $\mathrm{Octahedral} \mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6{\mathrm{Cl}}_3$
D) $\mathrm{Squareplanar} \mathrm{Pd}{\left({\mathrm{NH}}_3\right)}_3{\mathrm{Br}}^{+}$

E) $\mathrm{Octahedral} \mathrm{Co}{(\mathrm{en}{)}_3}^{3+}$