Atomic numbers of $Cr$ and $Fe$ are respectively $24$ and $26$. Which of the following is paramagnetic with the spin of the electron?

Atoms, ions or molecules having unpaired electrons are paramagnetic. in ${\left[Cr{\left(N{H}_3\right)}_6\right]}^{3+}$, Cr is present as Cr (III).
$C{r}^{3+}=1s^2,2s^{2}2p^6,3s^{2}3p^{6}3d^3$ In excited state

Number of unpaired electrons = 3, so it is paramagnetic while rest of the species are diamagnetic.