Which from following molecules serves as fibrous content of food only and useful for bowel movement in humans?

Step-by-step solution

Dietary fiber refers to indigestible polysaccharides that provide bulk for bowel function. Amylopectin, amylose, and glycogen are all digestible by human enzymes and serve as energy sources, not solely as fiber. Cellulose, composed of glucose units linked by -1,4-glycosidic bonds, cannot be hydrolyzed due to the absence of cellulase in humans. It passes through the digestive tract undigested, adding bulk to stool and facilitating bowel movements.