Which xylene is most easily sulphonated?

Which of the following compounds is used for the laboratory preparation of benzene?

Given below are two statements,one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : Benzene is more stable than hypothetical cyclohexatriene.
Reason $R$ : The delocalized $\pi$ electron cloud is attracted more strongly by nuclei of carbon atoms.
In the light of the above statements,choose the correct answer from the options given below:

In chlorination of benzene,the reactive species is

Which compound is formed when benzene is boiled with concentrated $HCl$?

Which of the following compounds is not aromatic?