Which of the following describes a primary function of the digestive system?

• A. Ingests food/fluids, excretes waste, and prepares carbs/fats/proteins.
• B. Regulates body temperature.
• C. Moves blood through the body.
• D. Filters air to the lungs.

Answer: (A)

The digestive system’s main job is to handle intake, processing, and elimination of food and fluids. It ingests what you eat and drink, breaks carbohydrates, fats, and proteins into smaller components so the body can use them, and ultimately eliminates waste. This focus on taking in nutrients and turning them into usable energy and building blocks is what makes the described function the best fit. The other listed roles belong to different systems: regulating body temperature is handled by the body's temperature-control mechanisms, moving blood through the body is a circulatory function, and filtering air for the lungs is the job of the respiratory system.