Answer : The correct option is, Lipid.
Carbohydrate : It is the most common type of organic compound. It contain only carbon (C), hydrogen (H), and oxygen (O) atoms.
It is built of small repeating units that form bonds with each other to make a larger
molecule. It is a long chain. It is also used for energy storage in living things.
Generally, all the carbohydrates are soluble in in water.
Lipid : Lipids are organic compounds which contain carbon, hydrogen, and oxygen atoms. It consist of fatty
acids, with or without additional molecules. Fatty acids are the organic molecules that have the general
formula , where ‘n’ ranges from 2 to 28 and always an even number. It is a long chain.
All the lipids are insoluble in polar solvent like water but are soluble in non-polar solvents. It is also used for energy storage in living things.
Monosaccharide : It is defined as the small repeating units (monomers). A monosaccharide contains carbon, hydrogen, and oxygen.
The general formula for a monosaccharide is, , where n can be any number greater than two. For
example, if n is 6, then the formula can be written as, . This is the formula of glucose. It is soluble in water.
Protein : It is an organic compound which contain carbon, hydrogen, oxygen, nitrogen, and in some
cases sulfur. They are made up of small molecules called amino acids.
All the structures are shown below.