Identify the incorrect statements from the following. I. Tin in +2...

Identify the incorrect statements from the following. I. Tin in +2 state acts as reducing agent while lead in +4 state acts as strong oxidising agent. II. Silicon exists as both $\left[\mathrm{SiF}_6\right]^{2-}$ and $\left[\mathrm{SiCl}_6\right]^{2-}$ forms. III. The hybridisation of carbon in fullerene is $s p^3$. IV. Among $\mathrm{Ge}, \mathrm{Sn}$ and $\mathrm{Pb}$ lowest melting point is for $\mathrm{Sn}$.