Find the number of complexes which satisfy at least three of the following four conditions : (a) Primary valence • 3 (b) Secondary valence= 6 (c) Oxidation number of central atom > +3 (d) Number of ions per molecule> 3

I. $\left[\mathrm{Pt}{\left({\mathrm{NH}}_3\right)}_4\right]\left[{\mathrm{PtCl}}_6\right]$         II. $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_3$

III. $\left[\mathrm{Co}{\left({\mathrm{NH}}_3\right)}_5\left({\mathrm{OH}}_2\right)\right]{\mathrm{Cl}}_3$      IV. $\left[\mathrm{Pt}{\left({\mathrm{NH}}_3\right)}_6\right]{\mathrm{Cl}}_4$

V. $\mathrm{K}\left[{\mathrm{PtCl}}_5\left({\mathrm{NH}}_3\right)\right]$                    VI. ${\left[{\mathrm{CoCl}}_2,(en{)}_2\right]}^{+}$, 

VII. $\left[\mathrm{Ni}(\mathrm{CO}{)}_4\right]$                            VIII.$\left[\mathrm{Co}\right(\mathrm{EDTA}){]}^{-}$