Which of the following complexes exhibits the highest paramagnetic behaviour?
where gly=glycine, en=ethylenediamine and bipy =bipyridyl
(At. no. $Ti=22,V=23,Fe=26,Co=27$)

The electronic configuration of $V\left(23\right)=\left[Ar\right]4s^2,3d^3$
Let in ${\left[V{\left(gly\right)}_2{\left(OH\right)}_2{\left(N{H}_3\right)}_2\right]}^{+}$ oxidation state of V is x.
$x+\left(-1\right)\times 2+\left(-1\right)2+\left(0\times 2\right)=+1$
$x=+5$
$V^{5+}=\left[Ar\right]4s^0,3d^0$ (no unpaired electrons)
Theelectronic configuration of
$Fe\left(26\right)=\left[Ar\right]4s^2,3d^6$
Let the oxidation state of ${\left[Fe\left(en\right)\left(ppy\right){\left(N{H}_3\right)}_2\right]}^{2+}$ is x.
$\left[x+\left(0\right)+\left(0\right)+\left(0\right)\times 2\right]=+2$
$x=+2$
$F{e}^{2+}=\left[Ar\right],3d^6\left(\because 4\text{unpaired electron}\right)$ but, bpy, en and $N{H}_3$ all are strong field ligands, so pairing occurs and thus, $F{e}^{2+}$ contains no unpaired electron
The electronic configuration of
$Co\left(27\right)=\left[Ar\right]4s^2,3d^7$
Let the oxidation state Co in ${\left[Co{\left(ox\right)}_2{\left(OH\right)}_2\right]}^{-}$ is x
$x+\left(-2\right)\times 2+\left(-1\right)\times 2=-1$
$x=+5$
$C{o}^{5+}=\left[Ar\right].3d^4$ [4 unpaired electrons]
ox and OH are weak field ligands, thus pairing of electron units does not occur.
The electronic configuration of $Ti\left(22\right)=\left[Ar\right]4s^2,3d^2$
Oxidation state of Ti in ${\left[Ti{\left(N{H}_3\right)}_6\right]}^{3+}$ is 3.
$T{i}^{3+}=\left[Ar\right]3d^1$ (one unpaired electron) Hence, complex ${\left[Co{\left(ox\right)}_2{\left(OH\right)}_2\right]}^{-}$ has maximum number of unpaired electrons, thus show maximum paramagnetism