The correct option is D Left ventricle
Heart has four chambers- two upper atria and two lower ventricles. The right atrium receives deoxygenated blood from the body and pumps it to the right ventricle. The right ventricle pumps this deoxygenated blood into the lungs. Left atrium receives the oxygenated blood from the lungs and pumps it to the left ventricle, from where it is circulated to all parts of the body, through aorta.