Final answer:
Starch is the polysaccharide among the options provided, serving as an energy storage molecule in plants and composed of glucose units.
Step-by-step explanation:
The polysaccharide among the following options is B. Starch. Polysaccharides are long-chain polymers made of monosaccharides joined together by glycosidic linkages. Starch is a homopolysaccharide composed of glucose units and is used as an energy storage molecule in plants. It is distinguishable from other polysaccharides like glycogen, which is the animal equivalent, and cellulose, which is a structural component in plant cell walls.
Three important polysaccharides to note are starch, glycogen, and cellulose. Starch and glycogen are energy storage molecules in plants and animals, respectively, while cellulose serves a structural role. All three are made up of glucose units but differ in their linkage orientation and structure, with starch being a branched molecule.