What is the main function of the intestines in human digestion?

The main function of the intestines in human digestion is the absorption of nutrients and water. The intestines, particularly the small intestine, are lined with tiny, finger-like projections called villi and microvilli, which increase the surface area for absorption. As food passes through this part of the digestive system, nutrients such as carbohydrates, proteins, fats, vitamins, and minerals are absorbed into the bloodstream. Additionally, the intestines also play a critical role in absorbing water, which is essential for maintaining hydration and proper bodily functions.

While the other options describe various digestive processes, they do not encapsulate the primary purpose of the intestines. Mechanical breakdown of food mainly occurs in the mouth and stomach, storage of waste products is primarily a function of the large intestine, and the production of digestive enzymes mainly occurs in glands and organs such as the pancreas and salivary glands, rather than in the intestines themselves. Therefore, absorption of nutrients and water is the correct answer, as it emphasizes the central role of the intestines in completing the digestive process.