Consider the following statements: 

Statement-I: ${\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_6\right]}^{3+}$ is an inner orbital complex with crystal field stabilization energy equal to $-1.2{\mathrm{\Delta }}_0$

Statement-2: The complex formed by joining the ${\mathrm{CN}}^{-}$ ligands to ${\mathrm{Fe}}^{3+}$ ion has theoretical value of 'spin only' magnetic moment equal to 1. 73 BM

Statement-3 ${\mathrm{Na}}_2\mathrm{S}+{\mathrm{Na}}_2\left[\mathrm{Fe}(\mathrm{CN}{)}_5\mathrm{NO}\right]\to {\mathrm{Na}}_4$ $\left[\mathrm{Fe}(\mathrm{CN}{)}_5\mathrm{NOS}\right]$ In reactant and product the oxidation states of iron are same 

and arrange in the order of true/false.

Since number of unpaired electrons obtained by joining the  ${\mathrm{CN}}^{-}$ ligand to  ${\mathrm{Fe}}^{3+}$ due to which its magnetic  moment is 1.73 BM.

Since ${\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_6\right]}^{3+}$ exist in the $t_{2}g$ orbital and having oxidation state 3 is an inner orbital complex with  crystal field stabilization energy equal to $-1.2{\mathrm{\Delta }}_0$ 

Since the value of Fe in reactant is +3 and product is +2 option C is incorrect.
Oxidation state in reactant

$\begin{array}{l}x+5(-1)+0=-2\\ x=+3\end{array}$

Oxidation state of Fe in product (y)

$\begin{array}{c}y+5(-1)+1(-1)=-4\\ y=+2\end{array}$

Hence the correct option is B.