Why Are Alkynes Less Reactive Toward Electrophilic Addition

Why are alkynes less reactive toward electrophilic addition?

A) Triple bonds are stronger than double bonds.
B) Only one ? bond must be broken in the addition of an electrophile to an alkene.
C) The ?-complex that is formed from an alkyne is less stable than the alkyl cation intermediate that is formed from an alkene.
D) Alkynes are less stable than alkenes.
E) Hyperconjugation stabilizes the intermediate from an alkyne more than the intermediate from an alkene.