Which component is NOT a basic necessity for the body's function?

Glycogen is not considered a basic necessity for the body's immediate function in the same way that the other options are. While glycogen serves as a stored form of glucose and is critical for energy supply during physical activity, the body can function without it in the short term by utilizing other energy sources such as fats and proteins.

In contrast, water is essential for maintaining hydration and supporting vital processes like temperature regulation and nutrient transport. Carbohydrates are important as a primary energy source for the body, particularly for the brain and muscles during exercise. Proteins play a crucial role in building and repairing tissues, as well as in various metabolic functions.

Thus, although glycogen is valuable for energy storage, it is not one of the fundamental components necessary for basic body functions in the same way as water, carbohydrates, and proteins are.