Question

What carbocation is most stable?

Answer 1

Check below

Explanation:

This answer is generalised to all compounds for stability.

1--Aromaticity -

You should check whether it satisfies the conditions for aromaticity.They are as follows:-
1-cyclic
2-all atoms must be `sp` or `sp^2` hybridised.
3-Its must follow Huckels rule.

2--Resonance
After aromaticity we check resonance.
Remember if the compound is aromatic ,the is more stable than resonating compound.(Exception might be few)
3----Hyperconjugation.

Check the number of `alpha` H.
More is the `alpha H` more the hypergujation.
Remember this will be highly needed to check carbocation.
4--Inductive effect.
5--Cross conjugation.