What is the number of unpaired electrons in $[Co(NH_3)_6]^{3+}$ complex?

The pair$(s)$ of complexes wherein both exhibit tetrahedral geometry is(are):
Note: $py = \text{pyridine}$
Given: Atomic numbers of $Fe, Co, Ni$ and $Cu$ are $26, 27, 28$ and $29$,respectively.
$(A)$ $[FeCl_4]^-$ and $[Fe(CO)_4]^{2-}$
$(B)$ $[Co(CO)_4]^-$ and $[CoCl_4]^{2-}$
$(C)$ $[Ni(CO)_4]$ and $[Ni(CN)_4]^{2-}$
$(D)$ $[Cu(py)_4]^+$ and $[Cu(CN)_4]^{3-}$

The hybridization observed in the $[PtCl_6]^{2-}$ ion is .......

The geometries of $Ni(CO)_4$ and $Ni(PPh_3)_2Cl_2$ are:

Which of the following complex ions has $0$ $d$-electrons in the central metal atom? (Atomic numbers: $Cr = 24, Mn = 25, Fe = 26, Co = 27$)

Match List-$I$ with List-$II$:

List-$I$ (Tetrahedral Complex)	List-$II$ (Electronic configuration)
$A$. $TiCl_4$	$I$. $e^2, t_2^0$
$B$. $[FeO_4]^{2-}$	$II$. $e^4, t_2^3$
$C$. $[FeCl_4]^{-}$	$III$. $e^0, t_2^0$
$D$. $[CoCl_4]^{2-}$	$IV$. $e^2, t_2^3$

Choose the correct answer from the options given below: