Unsaturated hydrocarbons are organic compounds that are entirely made up of carbon and hydrogen atoms and consist of a double or a triple bond.

Unsaturated hydrocarbons are compounds composed of carbon and hydrogen atoms, with one or more carbon-carbon double or triple bonds in their chemical structure.

In other words, unsaturated hydrocarbons are the Alkenes(C=C) and the Alkynes (C≡C). Hence, propene is the only alkene member in the given options.