What is the primary function of the circulatory system?

The primary function of the circulatory system is to carry oxygen and nutrients to body cells. This system consists of the heart, blood, and blood vessels, which work together to transport essential substances throughout the body. Oxygen, obtained from the lungs, is delivered to the cells for energy production, while nutrients, absorbed from the digestive system, are also distributed to cells for various metabolic processes. This transportation is crucial for maintaining the health and functionality of tissues and organs, enabling them to perform their specific roles effectively.

The other options clearly relate to functions of different body systems. For instance, the function of filtering blood and producing urine is associated with the renal system. The respiratory system is responsible for the exchange of gases, such as taking in oxygen and eliminating carbon dioxide. Digestion and absorption of nutrients fall under the digestive system's responsibilities. In summary, the circulatory system's vital role in delivering oxygen and nutrients is essential for overall body health and function.