Final answer:
The name given to polysaccharides that humans can't digest is Cellulose. It is a component of plant cell walls and is classified as dietary fiber because it assists in the passage through the digestive system.
Step-by-step explanation:
The name given to polysaccharides that cannot be digested by human digestive enzymes, and therefore cannot be absorbed is B. Cellulose. Cellulose is a homopolysaccharide made up of D-glucose units linked by β-1→ 4 glycosidic linkages. Unlike starch and glycogen, which are also polysaccharides composed of glucose units, cellulose cannot be broken down by the human digestive system because humans lack the necessary enzyme cellulase to digest it. Therefore, cellulose passes through the digestive tract essentially undigested and is referred to as dietary fiber or roughage, which aids in maintaining a healthy digestive system.