Which statement best describes the primary function of the digestive system?

• A. Transports Oxygen
• B. Breaks Down Food
• C. Filters Waste
• D. Regulates Hormones

Answer: (B)

The digestive system’s main job is to convert the food you eat into nutrients your body can use for energy, growth, and repair. It does this through mechanical actions like chewing and stomach mixing, plus chemical digestion with enzymes and acids that break carbohydrates, proteins, and fats into simple molecules. Those nutrients are absorbed mainly in the small intestine and then delivered to cells throughout the body, while indigestible material is eliminated as waste.

Transports Oxygen belongs to the respiratory and circulatory systems, which move oxygen from the lungs to tissues. Filtering waste is primarily the role of the kidneys and liver; digestion handles processing and elimination of indigestible material rather than filtering bodily wastes. Regulating hormones can occur as part of digestion, but the primary purpose of the digestive system is breaking down food and absorbing nutrients.