n-Heptane when heated to 800k at high pressure in the presence of  ${\mathrm{Cr}}_2{\mathrm{O}}_3/{\mathrm{Al}}_2{\mathrm{O}}_3$ gives

• A

  Xylene

• B

  2-methyl hexane

• C

  1-Heprene

• D

  Toluene