[Moneyking]

Which of the following statement applies to unsaturated  hydrocarbons:

a) the names of the compounds end in `ene`
b) the prefix `butyl` denotes three carbon atoms
c) the are quite unreactive
d) the most characteristic type of reaction is substitution
e) all of the C-C bonds are single bonds

All of them are false except for a, and a is kind of not true as well

[Aegis6]

Unsaturated hydrocarbons are those which have at least one double or triple bond in them. Whereas A is not entirely true, as it is possible for unsaturated hydrocarbons to end in -yne, the other options are entirely false, thus making A the best possible choice provided.

Further, I am not sure whether this problem is meant to be looked at from a biochemistry or organic chemistry standpoint, but if it is biochemistry, triple bonds are exceedingly rare in biochemical systems which may be why -yne wasn't listed as part of A.