For the tetrahedral complex $[MnBr_4]^{2-}$, the spin-only magnetic moment value is $....$ (At. no. of $Mn = 25$) (in $BM$)

Which of the following pairs of transition metal ions have the same calculated values of magnetic moment?

The number of isomers possible for the square planar complex $K_2[PdClBr_2(SCN)]$ is

Among the following complexes,the one that can exhibit optical activity is

The pair$(s)$ of coordination complexes/ions exhibiting the same kind of isomerism is(are)
$(A)$ $[Cr(NH_3)_5Cl]Cl_2$ and $[Cr(NH_3)_4Cl_2]Cl$
$(B)$ $[Co(NH_3)_4Cl_2]^+$ and $[Pt(NH_3)_2(H_2O)Cl]^+$
$(C)$ $[CoBr_2Cl_2]^{2-}$ and $[PtBr_2Cl_2]^{2-}$
$(D)$ $[Pt(NH_3)_3(NO_3)]Cl$ and $[Pt(NH_3)_3Cl]Br$

The number of geometrical isomers found in the metal complexes $[PtCl_2(NH_3)_2]$,$[Ni(CO)_4]$,$[Ru(H_2O)_3Cl_3]$ and $[CoCl_2(NH_3)_4]^+$ respectively,are :