Consider the following statements : 

Statement-I: The ${\left[\mathrm{Co}(\mathrm{ox}{)}_3\right]}^{3-}$ complex is diamagnetic and gains stability through chelation. 

Statement-2: The ${\left[\mathrm{Co}{\left({\mathrm{NO}}_2\right)}_6\right]}^4$ is an inner orbital complex involving $d^{2}s{p}^3$ hybridizations and is paramagnetic. 

Statement-3: The complex ${\left[{\mathrm{PtCl}}_4\right]}^{2-}$ is square planar and diamagnetic. and arrange in the order of true/false :

Since ${\left[\mathrm{Co}(\mathrm{ox}{)}_3\right]}^{3-}$ is a chelating ligand, exhibits $d^{2}s{p}^3$ hydrolyzation, and is diamagnetic they are more stable.

${\mathrm{NO}}_2^{-}$ is a more potent ligand, and its $d^7$ configuration results in one of the 3d-electron leaps to higher energy orbitals, which gives it the $d^{2}s{p}^3$ hybridization and complex paramagnetic property.

Pt(II) has a $5d^8$ configuration with a higher CFSE, according to  $\mathrm{CFSE}{\left[{\mathrm{PtCl}}_{\mathrm{4}}\right]}^{\mathit{2}\mathit{-}}$

Hence, the correct option is Ạ