The correct order of the calculated spin only magnetic moments of complexes (A) to (D) is:

$\left(\mathrm{A}\right) \mathrm{Ni}{\left(\mathrm{CO}\right)}_4 \left(\mathrm{B}\right) \left[\mathrm{Ni}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]{\mathrm{Cl}}_2 \left(\mathrm{C}\right) {\mathrm{Na}}_2\left[\mathrm{Ni}{\left(\mathrm{CN}\right)}_4\right] \left(\mathrm{D}\right) {\mathrm{PdCl}}_2{\left({\mathrm{PPh}}_3\right)}_2$