$[Mn(CO)_4 NO]$ is diamagnetic because

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

Match List-$I$ with List-$II$.

List-$I$	List-$II$
$A. Ni(CO)_4$	$I. sp^3$
$B. [Ni(CN)_4]^{2-}$	$II. sp^3d^2$
$C. [Co(CN)_6]^{3-}$	$III. d^2sp^3$
$D. [CoF_6]^{3-}$	$IV. dsp^2$

Choose the correct answer from the options given below.

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

List-$I$	List-$II$
$A. K_2[Ni(CN)_4]$	$I. sp^3$
$B. [Ni(CO)_4]$	$II. sp^3d^2$
$C. [Co(NH_3)_6]Cl_3$	$III. dsp^2$
$D. Na_3[CoF_6]$	$IV. d^2sp^3$

Choose the correct answer from the options given below:

Which of the following sequences of hybridisation, geometry, and magnetic nature are correct for the given coordination compounds?
$A.$ $[NiCl_4]^{2-}$ – $sp^3$, tetrahedral, paramagnetic  
$B.$ $[Ni(NH_3)_6]^{2+}$ – $sp^3d^2$, octahedral, paramagnetic  
$C.$ $[Ni(CO)_4]$ – $sp^3$, tetrahedral, paramagnetic  
$D.$ $[Ni(CN)_4]^{2-}$ – $dsp^2$, square planar, diamagnetic  
Choose the correct answer from the options given below:

Explain why $[Co(NH_{3})_{6}]^{3+}$ is an inner orbital complex whereas $[Ni(NH_{3})_{6}]^{2+}$ is an outer orbital complex.