Answer: PULMONARY ARTERY.
Explanation: Deoxygenated blood enters the right atrium through the superior and inferior vena cava,the right atrium contracts and the tricuspid valve opens and the blood from the right atrium empties into the right ventricle then the tricuspid valve closes to prevent the backflow of blood.
The right ventricle further contracts and the pulmonary valve opens,the blood from the right ventricle emptied into the pulmonary trunk and further into the right and left pulmonary arteries which empties into the right and left lungs.
Inside the lungs,there is exchange of gases, CO2 is given out for expiration and oxygen is taken in making the blood oxygenated.
This oxygenated blood enters into the left atrium through the pulmonary veins,the left atrium contracts and the mitral valve opens allowing blood from the left atrium to empty into the left ventricle and the valve closes to prevent the backflow of blood,the left ventricle further contracts,the aortic valve opens and the blood empties into the aortic trunk and up to the arch of aorta from where it goes into systemic circulation via the brachiocephalic trunk,left common carotid artery and left subclavian artery.
All the arteries in the body carry oxygenated blood except pulmonary artery which carries deoxygenated blood.