Correct Answer: B

Rationale: The primary function of the heart is to pump blood throughout the body, supplying oxygen and nutrients to tissues while removing waste products like carbon dioxide. The heart is a muscular organ divided into four chambers — two atria and two ventricles — that work in a coordinated rhythm controlled by electrical impulses. The right side pumps deoxygenated blood to the lungs for oxygenation, while the left side pumps oxygenated blood to the rest of the body. This continuous circulation is vital for sustaining life, supporting metabolism, and maintaining homeostasis across all bodily systems.

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