The correct option is C Lipid
Biomacromolecules are those molecules which have molecular weight greater than 1 kDa. There are four major classes of biological macromolecules - carbohydrates, lipids, proteins, and nucleic acids.
Lipids have a molecular weight less than 1 kDa. They are a part of the membranes in a cell. When the cell structure is disrupted, these molecules form vescicles and become part of the acid insoluble pool. Hence they are not strictly biomacromolecules.