2 3 and 4
@Rushabh-Jain 2) d
None of them are aromatic
No close conjugation.
These structures exists in above forms
As the ring becomes aromatic
So answer is 1st and 3rd structure
1st - yes most stable resonating structure contributes the most to the resonance hybrid
2)&4) true , the skeleton of the compound must remain same.
Only the position of pair of electron changes
Answer:A B D