C₃H₈ belongs to the homologous series of:

Alkanes

The correct answer is option 3. Alkanes.

\(C_3H_8\) belongs to the homologous series of Alkanes.

Alkanes are a homologous series of hydrocarbons characterized by single bonds between carbon atoms. The general formula for alkanes is \(C_nH_{2n+2}\), where n represents the number of carbon atoms in the molecule.

\(C_3H_8\) specifically represents propane, which is the simplest alkane with three carbon atoms in its chain. Therefore, propane \((C_3H_8)\) is a member of the alkane homologous series. So, the correct answer is Alkanes