Answer:
b, right atrium
Step-by-step explanation:
Deoxygenated blood from the body returns to the right atrium. When blood flows through the body, it carries oxygen to the cells and tissues, and it picks up waste products, such as carbon dioxide, along the way. When the blood reaches the end of its journey through the body, it is low in oxygen and high in waste products. This deoxygenated blood flows back to the heart, where it enters the right atrium, the upper chamber on the right side of the heart. From there, it is pumped into the right ventricle, which sends it to the lungs to be oxygenated. Once the blood is oxygenated, it returns to the left side of the heart, where it is pumped back out to the body to start the cycle over again.