The role of circulation is to deliver oxygen and remove wastes. Which option best describes this function?

• A. Deliver oxygen and remove wastes
• B. Maintain electrolyte balance
• C. Regulate temperature
• D. Control breathing rate

Answer: (A)

Circulation’s main job is to move oxygen from the lungs to the body's tissues and carry waste products, like carbon dioxide, back to organs that eliminate them. This direct delivery and removal is what the circulatory system does best, so describing it as delivering oxygen and removing wastes matches the fundamental function exactly.

Other roles mentioned—electrolyte balance, temperature regulation, and breathing rate—are important to overall physiology but are handled primarily by other systems (kidneys and fluids for electrolytes; skin, vessels, and hypothalamic mechanisms for temperature; brainstem and autonomic control for breathing). The circulation helps support these processes, but its core purpose remains transporting oxygen and removing wastes.