Both CO₂ and SiO₂ Appear to Have Valid Lewis Structures

Multiple Choice

Both CO₂ and SiO₂ appear to have valid Lewis structures.Using the molecular orbital model,why then are CO₂ molecules stable and SiO₂ molecules not stable?

A) CO₂ is able to form sigma bonds and SiO₂ is not.
B) The silicon 3p valence orbitals do not overlap very effectively with the smaller oxygen 2p orbitals.
C) The carbon atom is larger than the silicon atom,giving carbon a higher electron density and thus better pi bonding.
D) Silicon prefers to bond to other silicon atoms over oxygen atoms.
E) At least two of the above are correct.