Which body system circulates blood and lymph through the body, including the heart and glands?

• A. Immune system
• B. Cardiovascular system
• C. Circulatory system
• D. Lymphatic system

Answer: (C)

The circulatory system is about moving fluids through the body, including both blood and lymph. Blood is pumped by the heart through blood vessels to deliver oxygen and nutrients to tissues. Lymph flows through the lymphatic vessels, helping with immune function and fluid balance. Hormones from glands travel in the bloodstream to reach their targets, so the circulatory system also supports glands by distributing hormones and immune cells where needed. Since the description specifies circulating both blood and lymph and mentions the heart and glands, this broader network best fits. The immune system centers on defense, not fluid movement; the lymphatic system handles lymph but doesn’t move blood; the cardiovascular system focuses on blood flow but doesn’t explicitly describe lymph circulation, so the circulatory system is the most complete choice.