A student researcher calculated the number of moles of hydrogen used per ... ...

A student researcher calculated the number of moles of hydrogen used per mol for the hydrogenation of an unsaturated (only double bonds) aliphatic non-cyclic hydrocarbon compound. If the number of moles of hydrogen used for the complete hydrogenation of each mol of the hydrocarbon is eight, how many double bonds were there in the compound that was hydrogenated?  
(A) two
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in 16. Alkenes