What form of energy storage is primarily found in the liver and muscles?

Glycogen is the correct answer as it is the primary form of energy storage found in both the liver and muscles. Glycogen is a polysaccharide that serves as a readily available source of glucose, which the body uses for energy. In the liver, glycogen can be converted back into glucose and released into the bloodstream to maintain blood sugar levels, particularly between meals or during physical activity. In muscles, glycogen is stored and utilized locally to fuel muscle contractions during exercise.

While proteins and fats are also forms of energy storage in the body, they do not serve the same immediate energy needs as glycogen does, particularly for the quick energy requirements of muscle activity. Starch is a form of carbohydrate storage primarily found in plants, not in animal tissues like the liver and muscles. Therefore, glycogen is uniquely suited for the energy storage requirements of these tissues, making it the appropriate choice.