Determining the stability of four organic compounds given below

![enter image description here](https://i.stack.imgur.com/zP2SQ.jpg)


Answer given is a but how on earth is it possible because here one C Atom has 5 covalent bonds. Infact the aromatic character is decreased. I think c is correct because of resonance structure. But why the anser is a? Can anyone explain please? 




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For halogen is in meta position ? So -I effect of NO2 effecting? 




![enter image description here](https://i.stack.imgur.com/igOk4.jpg)![enter image description here](https://i.stack.imgur.com/SlK0I.jpg)![enter image description here](https://i.stack.imgur.com/OtcZq.jpg)


Ok I got the idea. It's because of hyperconjugation (mainly) and then about like charges on resonating structures or normal structures will decrease the stability 
And so the order is 


A>C>D>B
Or A>D>C>B


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