Which is more acidic? Which among these hydrocarbons is more acidic? 


Here, I thought about hyperconjugation. For this, I counted the alpha H i.e. the number of hydrogens attached to the carbon attached to a sp2 hybridized carbon. What I get is, (C) has most no. of those Hydrogens. So, my assumption is that  it should be more acidic. But that's not the case. Where am I going wrong?
Acidity is directly proportional to the stability of conjugate base. Aromatic compounds are very stable.

In essence only one compound after deprotonating is aromatic - which is the conjugate base of (A).