Which compound is an isomer of octane, ${{\text{C}}_{\text{8}}}{{\text{H}}_{{\text{18}}}}$?

A.     ${{\text{(C}}{{\text{H}}_{\text{3}}}{\text{)}}_{\text{2}}}{\text{CH(C}}{{\text{H}}_{\text{2}}}{{\text{)}}_{\text{2}}}{\text{CH(C}}{{\text{H}}_{\text{3}}}{{\text{)}}_{\text{2}}}$

B.     ${{\text{(C}}{{\text{H}}_{\text{3}}}{\text{)}}_{\text{2}}}{\text{CHC}}{{\text{H}}_{\text{2}}}{\text{CHCHC}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{3}}}$

C.     ${\text{C}}{{\text{H}}_{\text{3}}}{{\text{(C}}{{\text{H}}_{\text{2}}}{\text{)}}_{\text{5}}}{\text{C}}{{\text{H}}_{\text{3}}}$

D.     ${{\text{(C}}{{\text{H}}_{\text{3}}}{\text{)}}_{\text{2}}}{\text{CH(C}}{{\text{H}}_{\text{2}}}{{\text{)}}_{\text{2}}}{\text{CHCHC}}{{\text{H}}_{\text{3}}}$

A

There was some concern that this is not on the syllabus. The examiners consider the question to be a fair extension of assessment statement 10.1.5.