What is the function of the cardiovascular system?

• A. Regulates body temperature only
• B. Produces hormones
• C. Filters toxins
• D. Delivers nutrients and oxygen to cells and removes waste CO2

Answer: (D)

The main idea is that the cardiovascular system is about moving blood to keep every cell supplied and cleaned up. The heart acts as a pump that pushes blood through a vast network of vessels. Blood carries oxygen from the lungs and nutrients from the digestive system to all body tissues, where cells use those resources to produce energy. At the same time, blood picks up carbon dioxide and other wastes from cells and returns to the lungs and other organs to be removed from the body. This continuous circulation also lets the body transport hormones and immune cells, helping coordinate responses across systems and supporting heat distribution to help regulate body temperature.

So, delivering nutrients and oxygen to cells and removing waste CO2 captures the essential job. The option claiming regulation of body temperature only misses the broad transport and exchange roles. The idea that the system produces hormones isn’t accurate—the endocrine system does that. And filtering toxins isn’t a primary function of the cardiovascular system; organs like the liver and kidneys perform filtration, with the heart and vessels supporting circulation to those organs.