4. Which chamber does oxygenated blood enters the heart first?
a. Left Atrium
c. Left Ventricle
b. Right Atrium
d. Right Ventricie

5. Which blood vessel carries blood from the heart to the lungs to receive oxygen?
a. Aorta
b. Vena Cava
c. Pulmonary Vein
d. Pulmonary Artery​