Which of the following inner orbital complexes exhibits both geometrical and optical isomerism?

The type of isomerism shown by the complex $[CoCl_2(en)_2]$ is

$STATEMENT-1$: The geometrical isomers of the complex $[M(NH_3)_4Cl_2]$ are optically inactive.
$STATEMENT-2$: Both geometrical isomers of the complex $[M(NH_3)_4Cl_2]$ possess a plane of symmetry.

In $[Cr(C_2O_4)_3]^{3-}$,the isomerism shown is :-

Total number of unpaired electrons present in the central metal atoms/ions of $[Ni(CO)_{4}]$, $[NiCl_{4}]^{2-}$, $[PtCl_{2}(NH_{3})_{2}]$, $[Ni(CN)_{4}]^{2-}$ and $[Pt(CN)_{4}]^{2-}$ is . . . . . . .

Select the correct statement about $[Mn(CO)_4NO]$ which is diamagnetic.