Which one of the following does not exist?

(i) XeOF₄ (ii) NeF₂ (iii) XeF₂ (iv) XeF₆

NeF₂does not exist as it would require d orbital for bonding which Ne does not have as it belongs to period 2 and moreover a lot of energy would be used to excite the electrons to a higher energy level as the valence electrons are very close to the nucleus thus they experience strong electrostatic attraction.