The appropriate answer is D. storing sugar and providing structure. Polysaccharides are complex carbohydrates. Starch, glycogen and cellulose are polysaccharides in which the constituent molecules are made of several thousand glucose units linked in long chains. Glycogen is vital to nutrition because it is how the body stores excess glucose in muscles and in the liver.
The molecular structure of glycogen is similar to starch except that the polysaccharide chains are longer and more branched than in glycogen.
