Answer: Option (c) is the correct answer.
Explanation:
A long hydrocarbon chain that consists a terminal carboxylic group is known as a fatty acid.
An unsaturated fatty acid consists a double bond within the fatty acid chain. If a fatty acid contains more than one double bond then it is known as polyunsaturated fatty acid.
For example, oelic acid has chemical formula [tex]C_{18}H_{34}O_{2}[/tex] is an unsaturated fatty acid.
Therefore, we can conclude that option (c) represents an unsaturated fatty acid.
