Which of the following is a characteristic of an alkyne?

An alkyne is defined specifically as a type of hydrocarbon that contains at least one carbon-carbon triple bond. This characteristic distinguishes alkynes from other classes of hydrocarbons, such as alkanes and alkenes. Alkanes are saturated hydrocarbons that contain only single bonds, while alkenes contain at least one double bond. The key feature of alkynes, reflected in the correct answer, is the presence of one or more triple bonds between carbon atoms, which gives these compounds unique chemical properties and reactivity compared to their saturated and unsaturated counterparts.

The presence of a carbon-carbon triple bond significantly influences the physical and chemical properties of alkynes, such as their boiling points, bonding angles, and types of reactions they can undergo. Thus, recognizing the triple bond as the defining feature helps in identifying alkynes in organic compounds.