Resonance is $\underline{\text{NOT}}$ exhibited by

The correct stability order of the following resonance structures is:

Resonance in carbonate ion $CO_3^{2-}$ is shown below. Which of the following statements is true?

Which of the following compounds does not show resonance?

Which of the following statements is correct about $CO_3^{2-}$ ?
$A$. The hybridisation of the central atom is $sp^3$.
$B$. Its resonance structure has one $C-O$ single bond and two $C=O$ double bonds.
$C$. The average formal charge on each oxygen atom is $0.67$ units.
$D$. All $C-O$ bond lengths are equal.

The correct order of sulphur-oxygen bond order in $SO_3$,$S_2O_3^{2-}$,and $SO_4^{2-}$ is: