How would you convert the following compounds into benzene?
$(i)$ Ethyne
$(ii)$ Ethene
$(iii)$ Hexane

(N/A) $(i)$ Benzene from Ethyne: $3CH \equiv CH \xrightarrow{\text{Red hot Fe}, 873 \ K} \text{Benzene}$
$(ii)$ Benzene from Ethene: $CH_2=CH_2$ $\xrightarrow{Br_2/CCl_4} Br-CH_2-CH_2-Br$ $\xrightarrow{\text{alc. KOH}, \Delta} CH_2=CHBr$ $\xrightarrow{NaNH_2/\text{liq. } NH_3, 196 \ K} HC \equiv CH$ $\xrightarrow{\text{Red hot Fe}, 873 \ K} \text{Benzene}$
$(iii)$ Hexane to Benzene: $\text{Hexane}$ $\xrightarrow{Cr_2O_3, \text{Cyclization}} \text{Cyclohexane}$ $\xrightarrow{\text{Aromatization}} \text{Benzene}$