Which body system is correctly paired with its function?

The digestive system is correctly paired with its function because it primarily facilitates the breakdown of food and the absorption of nutrients into the bloodstream. Through a series of processes that involve mechanical and chemical digestion, nutrients such as carbohydrates, proteins, and fats are broken down into smaller molecules that can then be absorbed by the intestinal lining and transported into the bloodstream. This function is essential for providing the body with the nutrients it needs for energy, growth, and cellular repair.

The other options do not correctly align the body systems with their primary functions. For instance, while the respiratory system does play a vital role in gas exchange, it is not responsible for transporting oxygenated blood; that task is primarily carried out by the circulatory system. Similarly, the excretory system is involved in the elimination of waste products from the body but does not prevent harmful substances from entering; this function is more aligned with the integumentary system and other defense mechanisms. Lastly, while the endocrine system does indeed transport hormones, its primary role is to regulate bodily functions through hormone secretion rather than focusing solely on transportation.