Contributor `I` is the most stable as it has more number of covalent bonds, all of the atoms have a complete valence shell of electrons, and there is no chargae separation. Contributor `II` si less stabel as it involeves charge separation but carries negative charge on more electronegative `O` atom and positive charge on the less electronegative `C` atom. Contributor `III` is leaast stabel as it has positive charge on more electronegative `O` atm and negative chargae on less electronegative `C` atom. Thus, the relative order of stability is as follows.
`I gt II gt III`
