Type of isomerism which is shown by ${\left[{\mathrm{PtCl}}_2{\mathrm{Br}}_2\right]}^{2-}$ is also observed in:

• A

  ${\left[{\mathrm{CoCl}}_2{\mathrm{Br}}_2\right]}^{2-}$

• B

  ${\left[\mathrm{Co}{\left(\mathrm{en}\right)}_3\right]}^{3+}$

• C

  ${\left[{\mathrm{PtCl}}_4{\mathrm{Br}}_2\right]}^{2-}$

• D

  ${\left[{\mathrm{PtCl}}_3\left({\mathrm{NO}}_2\right)\right]}^{2-}$