What is the state of hybridisation of carbon in $(a)$ $CO_3^{2-}$,$(b)$ diamond,and $(c)$ graphite?

$NH_2CONH_2 + 2 H_2O \rightarrow [X] \rightleftharpoons 2 NH_3 + H_2O + [Y]$
The hybridization of carbon in $X$ and $Y$ respectively are

Determine the hybridization of the sulfur atom in the $SO_3$ molecule.

The nature of hybridization in the $NH_3$ molecule is

What is the hybridization of the iodine atom in $ICl_2^-$?

$A + 2Cl^{-} \rightarrow B$
Where $A$ is $PCl_4^+$ and $B$ is $PCl_6^-$.
Which of the following statements is $INCORRECT$:
$(I)$ From $B$ to $A$,the number of $d$-orbitals involved in hybridization increases.
$(II)$ From $A$ to $B$,the percentage of $p$-character in the $P-Cl$ bond increases.
$(III)$ The number of covalent bonds in $A$ and $B$ are the same.
$(IV)$ $B$ is a product of Lewis acid-base interaction,which is associated with super-octet molecules only.