yeah rajiv's answer is correct
@abhi: in fig II the two reso str. are equivalent. So, the two bond lengths are equal
Single bonds are longer than double bonds.
In case of the anion form of the acid, it is resonance stabilized, hence, the γ & δ bond lengths will be the same. (They have 1.5 bond order, and greater the bond order smaller is the bond length).
And α is a pure double bond, while β is a pure single bond.
Hence, the bond length order shall be:
B.L of β > γ = δ > α
yeah rajiv's answer is correct
@abhi: in fig II the two reso str. are equivalent. So, the two bond lengths are equal