Which of the following choices represents a function of the digestive system?

The digestive system plays a crucial role in obtaining nutrients from the food we consume and subsequently eliminating waste products from the body. This process involves several stages, starting with the ingestion of food, where it is broken down into its constituent parts through mechanical and chemical means. Nutrients such as carbohydrates, proteins, fats, vitamins, and minerals are extracted and absorbed primarily in the intestines and then transported through the bloodstream to various cells in the body for energy, growth, and repair. Meanwhile, undigested and unabsorbed materials are formed into waste and expelled from the body.

In contrast, continuous energy production is more directly associated with metabolic processes rather than the digestive system itself. Breaking down proteins for energy is somewhat misleading, as the digestive system's primary function is to break down food into nutrients, not solely focusing on proteins for energy. While the digestive system may have indirect relationships with hormones that regulate metabolism, hormone production is primarily handled by endocrine glands rather than being a direct function of the digestive system. Therefore, the correct choice clearly highlights the crucial roles of nutrient uptake and waste elimination within the digestive system.