Which kind of isomerism is exhibited by octahedral $\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_4{\mathrm{Br}}_2\mathrm{Cl}$?

• A

  Geometrical and Ionization

• B

  Geometrical and Optical

• C

  Optical and Ionization

• D

  Geometrical only