Which of the following complex ions is not diamagnetic ?

$\begin{array}{l}{\left[\mathrm{Cr}{\left({\mathrm{NH}}_3\right)}_6\right]}^{+3}\\ \mathrm{Cr}\left(\mathrm{Z}=24\right)......\left[\mathrm{Ar}\right]4{\mathrm{s}}^{1}3{\mathrm{d}}^5\\ {\mathrm{Cr}}^{+3}.......\left[\mathrm{Ar}\right]3{\mathrm{d}}^3\end{array}$

Irrespective of the field strength of ligands in octahedral ${\mathrm{Cr}}^{+3}$ complexes rearrangement does not occur.
Hybridization is ${\mathrm{d}}^2{\mathrm{sp}}^3$.  ${\mathrm{\mu }}_{\mathrm{s}}=\sqrt{3\left(3+2\right)}\mathrm{B}.\mathrm{M}.$
$\begin{array}{l}\left(1\right)......{\mathrm{Ti}}^{+4}.....\left[\mathrm{Ar}\right]\\ \left(3\right).....{\mathrm{Zn}}^{+2}.....\left[\mathrm{Ar}\right]3{\mathrm{d}}^{10}\\ \left(4\right).....{\mathrm{Sc}}^{+3}....\left[\mathrm{Ar}\right]\end{array}$
All these species do not have unpaired electrons.