Answer:
A. circulation
Explanation:
the heart is the central organ of the circulatory system. As the heart beats, it pumps blood through a system of blood vessels. the heart along with the circulatory system constitutes the circulatory system. The movement of blood through the heart and the body is called <em>circulation</em>.
Approximately 1.8 million people go bankrupt each year due to medical bills.
Because second hand smoke can and will affect the lungs of everyone who is around, not just the smokers
