The correct option is D Glucose units
Glycogen
Glycogen is a branched polysaccharide made up of only glucose residues and hence it is homopolysaccharide/ homopolymer. It contains α-1,4 glycosidic linkage at the unbranched part between glucose residues and α-1,6 glycosidic linkage at the branching points.
Glucose
Glucose is a monosaccharide and also a monomer of many disaccharides and polysaccharides such as glycogen, starch, cellulose.
Galactose
Galactose is a monosaccharide and has the same chemical formula as that of glucose.
Ribose
Ribose is a pentose sugar found in RNA (ribonucleic acid).
Amino acids
Amino acids are organic compounds that are the constituents
(monomers) of proteins.
Final answer a. Glucose units