Answer:
The right atria
Step-by-step explanation:
The heart is the core organ of the circulatory system responsible for pumping blood by the contraction of cardiac muscles which is then conveyed to other parts of the body through blood vessels. The heart possesses four chambers of which the two upper ones are called ATRIA and the two lower ones are called VENTRICLE.
Each side of the heart contains one atria and one ventricle. The atria allows blood into the heart while the ventricle allows blood out of the heart. However, during the pumping process, deoxygenated (without oxygen) and oxygenated (with oxygen) blood enters and leaves the heart. The right ATRIA is responsible for receiving deoxygenated blood into the heart while the left ATRIA receives oxygenated blood into the heart.