Which of the following does not obey the octet rule?

Which one of the following is a correct set?

Which one of the following is a Lewis acid?

If two different non-axial $d-$orbitals having $xz$ nodal plane form $\pi-$bond by overlapping each other,then the internuclear axis will be:

Select true or false statements :
$(a)$ Promotion of electron is essential condition prior to hybridisation
$(b)$ In $VSEPR$ theory,two or three electron pairs of a multiple bond are treated as a single super pair
$(c)$ Bond length for $CO_2$ lies between double and triple bonds
$(d)$ $Ne_2$ does not exist

What are the similarities and differences in the Lewis structures of $H_2SO_4$ and $SO_4^{2-}$?