Identify,from the following,the diamagnetic,tetrahedral complex.

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

List-$I$ (Complex/ion)	List-$II$ (Shape/geometry)
$A$. $[Pt(Cl)_2(NH_3)_2]$	$I$. Octahedral
$B$. $[Co(NH_3)_6]Cl_3$	$II$. Trigonal bipyramidal
$C$. $[NiCl_4]^{2-}$	$III$. Square planar
$D$. $[Fe(CO)_5]$	$IV$. Tetrahedral

$[Co(NH_3)_6]^{+2}$ is paramagnetic in nature due to the presence of unpaired $e^-$ in

What is the type of hybridisation and the geometry respectively found in $[CoF_{6}]^{3-}$?

Reaction of $[Co(H_2O)_6]^{2+}$ with excess ammonia and in the presence of oxygen results into a diamagnetic product. Number of electrons present in $t_{2g}$-orbitals of the product is $.....$ .

The number of isoelectronic species among $Sc^{3+}$,$Cr^{2+}$,$Mn^{3+}$,$Co^{3+}$,and $Fe^{3+}$ is $n$. If $n$ moles of $AgCl$ are formed during the reaction of the complex with the formula $CoCl_{3}(en)_{2}NH_{3}$ with excess $AgNO_{3}$,then the number of electrons present in the $t_{2g}$ orbital of the complex is . . . . . . .