Coordination Compounds

If $$\mathrm{Ni}^{2+}$$ is replaced by $$\mathrm{Pt}^{2+}$$ in the complex $$\left[\mathrm{NiCl}_{2} \mathrm{Br}_{2}\right]^{2-}$$, which of the following properties are expected to get changed ? A. Geometry B. Geometrical isomerism C. Optical isomerism D. Magnetic properties