Which of the following is part of the digestive system?

• A. Liver
• B. Heart
• C. Lungs
• D. Kidneys

Answer: (A)

The main idea is to recognize which organs belong to the digestive system and help break down and absorb nutrients. The liver fits here because it plays key roles in digestion: it produces bile, which is released into the small intestine to emulsify fats, and it processes nutrients absorbed from the gut. It also carries out metabolic tasks that support digestion, like converting excess glucose to glycogen and detoxifying substances.

The other organs belong to different body systems: the heart is part of the circulatory system and pumps blood; the lungs are part of the respiratory system and handle gas exchange; and the kidneys are part of the excretory system, filtering blood to form urine.