Which blood vessel contains blood that has high oxygen concentration, low carbon dioxide concentration, and high pressure?

1. aorta
2. pulmonary artery
3. pulmonary vein
4. vena cava

I wrote the answer as 3, but is wrong. Which one is the correct answer?

Pulmonary artery

the pulonary vein would be low pressure, it is just leaving the lung capilaries and going to the heart pump. what is the where does that blood exit the heart (high pressure)?

http://biology.about.com/od/anatomy/a/aa041207a.htm

4. vena cava

B

The correct answer is actually option 1, the aorta. The aorta is the main artery in the body that carries oxygen-rich blood from the heart to the rest of the body. The blood in the aorta contains high oxygen concentration because it has just been pumped out of the left ventricle of the heart, which receives freshly oxygenated blood from the lungs. In addition, the blood in the aorta has a high pressure since it is being pumped directly from the heart's left ventricle. On the other hand, the pulmonary artery carries deoxygenated blood from the heart to the lungs, the pulmonary vein carries oxygenated blood from the lungs to the heart, and the vena cava carries deoxygenated blood from the body back to the heart.