(a) C₂H₆ and C₄H₆

(b) C₆H₁₂ and C₅H₁₂

(c) C₄H₆ and C₆H₁₂

(d) C₂H₅ and C₄H₁₀

Solution:

Option (c) is the answer.

Unsaturated hydrocarbons are those that belong to the alkene or alkyne homologous series. The carbon atoms can be organised in straight chains, branching chains, or rings (cyclic compounds), as long as the molecule has at least one double bond (C=C) and/or one triple bond (CC).