Arteries are strong, elastic vessels that carry blood to the heart.

Persons with type AB blood are sometimes called universal recipients, not donors. This means they can safely receive a blood transfusion using any other blood type. Choice A is wrong because it confuses type AB blood with type O negative blood.

Type O negative blood is considered the universal donor type because it has no antigens on the surface of red blood cells and can be given to people of any blood type.

Type AB-positive blood is also considered the universal plasma donor type because it has both A and B antigens and can be given to patients with any blood type.

Plasma is the liquid part of blood that carries cells and proteins throughout the body.

The presence or absence of antigens and the Rh factor determine how a person’s immune system reacts to a blood transfusion or organ transplant.

Antigens are substances that can trigger an immune response if they are foreign to the body.

The Rh factor is a protein that can be either present (+) or absent (-) on the surface of red blood cells.

It is measured as part of a blood test and depends on the number and size of red blood cells. It is normally 40.7–50.3% for males and 36.1–44.3% for females.
Red blood cells contain hemoglobin, which transports oxygen and nutrients to the cells and tissues of the body.
Choice A is wrong because the color of plasma is not hematocrit.
Plasma is the liquid part of blood that carries blood cells and other substances.
Choice B is wrong because hematocrit is not a disease.
It is a test that can indicate conditions such as anemia or polycythemia.
Choice C is wrong because hematocrit is not a clotting factor.
Clotting factors are proteins that help the blood to clot and prevent bleeding.