Coordination Compounds

Arrange the following complexes in the increasing order of their spin only magnetic moment (in B.M)

I. $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-}$

II. $\left[\mathrm{MnCl}_4\right]^{2-}$

III. $\left[\mathrm{Mn}(\mathrm{CN})_6\right]^{4-}$

IV. $\left.\left[\mathrm{Cr}(\mathrm{NH})_3\right)_6\right]^{3+}$