Hint: Our body has various blood vessels that carry blood to and fro from the heart. Arteries are superficial while veins are quite deep. Capillaries form the smallest vessels in our body that help to diffuse the oxygen between the tissues.
Complete answer: Heart in our body pumps blood to the whole body. There are blood vessels which carry the deoxygenated blood to the heart and pump out the oxygenated blood in other vessels. The blood vessels carrying the blood away from the heart are the arteries while the vessels which bring blood from the body to the heart are called veins. Let us see which of the options carry the deoxygenated blood only. > Option A. Carotid artery: The vessels which carry the oxygenated blood to the head, brain and face are carotid arteries. We can feel them by placing our fingers on our side neck. The blood moves to the brain against the gravity pull so they have special arteries. Thus it will carry oxygenated blood only. > Option B. Pulmonary artery: Arteries carry blood away from the heart so the pulmonary artery is the one which leaves the right ventricle and brings the blood into the lungs to purify. Thus it will have deoxygenated blood always. > Option C. Pulmonary vein: The veins are the vessels carrying blood to the heart. So pulmonary vein is the vessel which brings the blood from the lungs after purification to the heart. Thus it will have oxygenated blood. > Option D. Aorta: It is the largest artery in our system which originates from the left ventricle, taking the oxygenated blood to the whole body.
So the answer is option B: Pulmonary artery
Note: Study of the heart is called Cardiology. Our heart is of the size of our fist. It can beat even when it is outside the body. Sometimes the blood in our vessels flows with great pressure, which causes high blood pressure. This prolonged state can rupture the vessels and this could be fatal.