Which one of the following functional groups is not meta directing?

In electrophilic aromatic substitution reactions of chlorobenzene,the $ortho/para$-directing ability of chlorine is due to its

In the nitration mixture,concentrated sulfuric acid $(H_2SO_4)$ is used as:

The major products $P$ and $Q$ formed in the following reaction schemes are:

$C_6H_6 + 3O_3$ $\longrightarrow X \stackrel{Zn / H_2O}{}$ ${\longrightarrow} Y$; $X$ and $Y$ are respectively

Rank the following compounds in decreasing order of reactivity towards Electrophilic Aromatic Substitution $(EAS)$ reaction:
$(a)$ $Toluene$
$(b)$ $Nitrobenzene$
$(c)$ $Benzene$
$(d)$ $Chlorobenzene$