The number of molecules/ions from the following in which the central atom is involved in $sp^3$ hybridization is: $NO_3^{-}, BCl_3, ClO_2^{-}, ClO_3$

Which of the following hybridisation results in non-planar orbitals?

$A + 2Cl^{-} \rightarrow B$
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.

Hybridisation states of $C$ in $CH_3^+$ and $CH_4$ are

As a result of $sp$ hybridization,we get

Which one has $sp^2$ hybridisation?