a
\(\mathop {\mathop {{C_6}{H_{14}}\,}\limits_{{\text{Hexane}}} \xrightarrow[\Delta ]{{{\text{Pyrolysis}}}}}\limits_{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \mathop {{C_2}{H_4}}\limits_{{\text{Ethene}}} + \mathop {{C_4}{H_{10}}}\limits_{{\text{Butane}}} \)