(N/A) When benzene is heated with $CH_3Cl$ in the presence of anhydrous $AlCl_3$,the primary product formed is toluene $(C_6H_5CH_3)$ via the Friedel-Crafts alkylation reaction.
The reaction is as follows:
$C_6H_6 + CH_3Cl \xrightarrow{AlCl_3} C_6H_5CH_3 + HCl$
Why:
$1$. The $-CH_3$ group is an electron-donating group,which activates the benzene ring towards further electrophilic substitution.
$2$. Because the $-CH_3$ group is ortho- and para-directing,the newly introduced methyl group will preferentially occupy the ortho and para positions of the toluene ring,leading to the formation of $o$-xylene and $p$-xylene if excess $CH_3Cl$ is present.