What is the magnetic moment value of $Ni^{2+}$ in an aqueous solution in Bohr Magnetons? (Atomic number: $Ni = 28$)

Out of the following two coordination entities,which is chiral (optically active)?
$(a)$ $cis-[CrCl_{2}(ox)_{2}]^{3-}$
$(b)$ $trans-[CrCl_{2}(ox)_{2}]^{3-}$

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

List-$I$	List-$II$
$(a).$ $[Co(NH_3)_6][Cr(CN)_6]$	$(i).$ Linkage isomerism
$(b).$ $[Co(NH_3)_3(NO_2)_3]$	$(ii).$ Solvate isomerism
$(c).$ $[Cr(H_2O)_6]Cl_3$	$(iii).$ Coordination isomerism
$(d).$ $cis-[CrCl_2(ox)_2]^{3-}$	$(iv).$ Optical isomerism

Choose the correct answer from the options given below:

Identify the type of isomer shown in the given structure of the coordination compound.

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

List-$I$ (Complex)	List-$II$ (Spin only magnetic moment in $B$.$M$.)
$A$. $[Cr(NH_3)_6]^{3+}$	$I$. $4.90$
$B$. $[NiCl_4]^{2-}$	$II$. $3.87$
$C$. $[CoF_6]^{3-}$	$III$. $0.0$
$D$. $[Ni(CN)_4]^{2-}$	$IV$. $2.83$

Choose the correct answer from the options given below:

Calculate the magnetic moment of the $Fe^{3+}$ ion in the $[Fe(CN)_6]^{3-}$ complex.