Which of the following compounds is a storage form of carbohydrate in animals?

Glycogen is the correct answer because it serves as the primary storage form of carbohydrates in animals. It is predominantly found in the liver and muscles, where it is synthesized from glucose when energy intake exceeds immediate energy needs. Glycogen can be rapidly mobilized to meet immediate energy demands, making it an essential compound for maintaining blood glucose levels and providing energy during physical activities.

In contrast, starch is the storage form of carbohydrates in plants, not animals. Cellulose is a structural component of plant cell walls and provides rigidity, and while it is a carbohydrate, it is not utilized as a storage form in animals. Sorbitol is a sugar alcohol often involved in metabolic processes but does not function as a carbohydrate storage form in the same way that glycogen does. Thus, glycogen stands out as the key compound for energy storage in the animal kingdom.