Answer:
The correct answer will be option- A.
Step-by-step explanation:
Four types of macromolecules are present in the living organisms which are lipids, carbohydrates, DNA and proteins.
All of these molecules play a different role in the organism and are formed of different monomers- the smallest structural unit of macro-molecules.
The DNA present in the organism differs from other molecules due to different monomer called "nucleotides" which join end to end to form long polymer chains.
Thus, option- A is the correct answer.