The pulmonary arteries are the only arteries that contain oxygen-poor blood because it carries blood into the lungs to be oxygenated. By definition, arteries carry blood away from the heart and veins carry blood to the heart. However, the pulmonary vein is the only vein in the body that carries oxygen-rich blood (from the lungs back to the heart to be pumped into the rest of the body) and the pulmonary artery is the only artery in the body that carries oxygen-poor blood (to the lungs to be oxygenated before being sent to the heart to be pumped into the rest of the body. The carotid artery is in the neck and delivers oxygen-rich blood to head. The femoral artery is in the leg and delivers oxygen-rich blood to the leg. The aorta is the main artery that delivers blood from the left ventricle of the heart to the rest of the body. 

Blood types are named according to the antigens present on the surface of a person's red blood cells, specifically the ABO and Rh antigens. AB+ blood has all three antigens and therefore none of the antibodies, meaning it can receive any blood type without having an immune reaction to the donor blood. 

O- blood is unique from the other blood types due to its lack of ABO and Rh antigens. Unlike A and B, O is used to denote no antigens rather than an "O type" of antigen. As a result, it can be given to any other blood type since there are no antigens on the red blood cells to have an immune reaction the recipients own natural antibodies. 

The function of the lymphatic system is to keep fluids out of the interstitium and connective tissue by returning it to the blood. Fluid leaks out of capillaries because of their thin walls. The lymphatic vessels collect this fluid and return it to the heart. When the lymphatic system is impaired, this fluid can accumulate in the tissue and cause swelling, known as edema.

Most of the lymph re-enters the venous circulation through the thoracic duct, and the volume is somewhere around a liter to a liter and a half per day.  

Deoxygenated blood enters the heart through the right atrium, where it then flows into the right ventricle. The right ventricle pumps the deoxygenated blood through thepulmonary arteries to the lungs, where it becomes oxygenated. Oxygenated blood returns to the heart through the pulmonary veins, which empty into the left atrium. Blood then flows into the left ventricle, which contracts to pump the blood through the aorta and toward the rest of the body.

In the circulatory system, the heart acts as the pump, the vessels are conduits allowing blood and lymph flow, and the transport fluid is the blood, which can deliver nutrients and oxygen to tissues and cells throughout the body. Thus, the primary purpose of the circulatory system is, as the correct answer choice states, to deliver oxygen to tissues and transport blood and lymph.

The respiratory system is responsible for gas exchange, while the excretory system is responsible for maintaining fluid balance. The immune system is responsible for destroying foreign pathogens.

There can be two classes of antigens on blood cells: one can distinguish ABO blood types and the second is the Rhesus factor (Rh factor), which determines positive or negative blood type.

A person with type O blood would not carry any antigens on their cells; however this individual’s plasma would contain anti-A and anti-B antibodies. Interestingly, this is why type O blood individuals are commonly known as universal donors, as their cells do not elicit immune responses from any other blood cell types. An individual with Rh^- would not carry the Rh factor antigen on the surface of their cells. Thus, O^-, correctly identifies the blood type of an individual lacking any of these antigens on their blood cells.

All of the given answer options are contained in blood at some point; however the main components are red blood cells (RBC’s), platelets, plasma, and white blood cells (WBC’s). Platelets are involved in coagulation, while white blood cells are involved in immunity. Plasma refers to the fluid matrix of the blood, and contains proteins, gases, amino acids, and hormones.

Hemoglobin is a specific protein located in red blood cells. Oxygen binds to hemoglobin for transport through the boold. Neither of these are considered major components of blood.

The universal donor blood type is O^-, because this blood can be transfused to any of the ABO blood types, as well as to those with Rh+ and Rh-. O-negative blood is devoid of any antigens, but carries antibodies against A, B, and Rh.

AB⁺ contains both A and B antigens that would elicit an immune responses against any blood containing anti-A or anti-B antibodies. However, AB blood can receive all types of blood because it contains no antibodies. Additionally, AB⁺ blood carries the Rh antigen and is void of Rh antibodies. This makes AB⁺ blood the universal acceptor.

The aorta is the largest artery in the body. Like other arteries, the aorta's walls are made up of several layers, one of the largest layers being an elastic layer, which stretches and recoils in response to high pressure blood being pumped through it. Also, recall that all arteries carry blood away from the heart. Blood from the left ventricle of the heart is pumped into the aorta through the aortic semilunar valve. The venae cavae are the largest veins in the body. Like all veins, they carry blood back to the heart. Although the pulmonary artery is quite large, it is not as large as the aorta. Recall that the left ventricle is larger than the right ventricle, and thus more blood is pumped from the left ventricle through the aorta than is pumped from the right ventricle through the pulmonary artery.