Answer : The correct option is, (D) unsaturated
Explanation :
As the organic compounds are classified into two categories which are acyclic (aliphatic) and cyclic (aromatic) compounds.
Acyclic compounds are also classified into two categories which are saturated and unsaturated compounds.
Saturated hydrocarbon : These are the compounds which containing single bonds between the carbon-carbon atoms. In saturated compounds, there are more number of hydrogen bonded with the carbon atom.
Unsaturated hydrocarbon : These are the compounds which containing double and triple bonds between the carbon-carbon atoms. In unsaturated compounds, there are less number of hydrogen bonded with the carbon atom.
Aromatic : Aromatic compounds are the type of an unsaturated compounds but it is not necessary that the unsaturated compounds are aromatic. It is a compound which containing the
electrons and all the
electrons are in conjugation.
Hence, if the carbon atom of hydrocarbon is bonded to less than 4 other atoms, the hydrocarbon is considered as unsaturated.