Answer:
A. Macromolecule
Explanation:
A macromolecule is commonly formed through polymerization which means the production of polymers. The polymers are usually formed when different monomers add up to form a bigger substance(polymer). Polymers are examples of macromolecules because they contain two or more monomers which has a lot of compounds embedded in them.
Macromolecules are very large molecule made up of many smaller molecules joined together and the other options such as carbohydrates, Lipid and nucleic are examples of macromolecules formed under suitable conditions.