Which of the following hybridisation has maximum $s-$character?

The correct order of increasing $s$-character (in percentage) in the hybrid orbitals of the following molecules/ions is: $(I) \, CO_3^{2-}$,$(II) \, XeF_4$,$(III) \, I_3^-$,$(IV) \, NCl_3$,$(V) \, BeCl_2$.

Consider the following reaction $BCl_3 + NH_3 \longrightarrow BCl_3 \cdot NH_3$. The geometries of $BCl_3$ and $BCl_3 \cdot NH_3$ respectively are

In $CO_2$,$C$ is $sp$ hybridised using $s$ and $p_x$ orbitals. Then:

The hybridisation of xenon atom in $XeF_4$ is

Which one of the following has the regular tetrahedral structure?
(Atomic no. : $B = 5, S = 16, Ni = 28, Xe = 54$)