Which of the following statements is not true about resonance?

Which of the following pairs does not represent resonating structures?

With respect to resonance structures of $CO_3^{2-}$ ion, which of the following statements are correct?
$(a)$ All $C – O$ bonds in $CO_3^{2-}$ are equivalent
$(b)$ There are three resonance structures possible for $CO_3^{2-}$ ion
$(c)$ The position of carbon and oxygen should change in every resonance structure
$(d)$ The formal charge on carbon atom is $0$

The $C-O$ bond length in $CO$,$CO_2$ and $CO_3^{2-}$ follows the order.

Which of the following is the most unstable resonating structure of phenol?

Explain with a suitable example that the resonance structures of a molecule do not represent its real structure and are hypothetical.