Final answer:
The respiratory system requires the cardiovascular system to deliver oxygen to the body's cells and remove carbon dioxide. This critical collaboration enables cells to perform necessary functions and maintain homeostasis.
Step-by-step explanation:
Conjunction of the Respiratory and Cardiovascular Systems
The respiratory system works in conjunction with the cardiovascular system to deliver oxygen to the cells of the body and remove carbon dioxide. Our bodies breathe in oxygen which the lungs absorb into the bloodstream. The cardiovascular system, consisting of the heart, blood vessels, and blood, then carries this oxygen-rich blood to every cell in the body. Simultaneously, it collects carbon dioxide, a waste product of metabolism, from the cells and transports it back to the lungs to be exhaled. Without this crucial collaboration, cells would not receive the needed oxygen to perform vital functions and maintain homeostasis. The correct answer to the student's question is A. cardiovascular.