Statement I ; Carboxylic acids stabilize through resonance.Statement II ;  Carboxylate ion is more resonance stabilized than carboxylic acid.

In the resonance structures of Carboxylic acid there is  charge separation and they are unequivalent and distinguishable moreover oxygen atom possess positive charge on it,  hence less stable.In the resonance structures of carboxylate ion there is no charge separation, they are equivalent and indistinguishable with oxygen atom bearing negative charge, hence more stable.