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

A person who is stressed usually will have increased blood pressure because stress causes the body to release a surge of hormones that make the heart beat faster and the blood vessels narrow.
This can cause a temporary spike in blood pressure, which usually returns to normal once the stressor is gone.
Choice A is wrong because resistance to infections is not increased by stress.
In fact, chronic stress can weaken the immune system and make a person more prone to infections.
Choice B is wrong because the activity of the spleen and other lymphatic organs is not increased by stress.
The spleen and other lymphatic organs are part of the immune system, which can be affected by chronic stress in a negative way.
Choice C is wrong because the number of lymphocytes in the blood is not increased by stress. Lymphocytes are a type of white blood cell that help fight infections.
Chronic stress can reduce the number and function of lymphocytes and impair the immune response.

A person with type AB blood can successfully receive blood from all blood types.
This is because type AB blood has both A and B antigens on the surface of red blood cells, and therefore does not have antibodies against either antigen in the plasma.
Type AB blood is also called the universal recipient.
Choice B is wrong because type AB blood can receive more than just type O blood.
Type O blood is the universal donor, meaning it can be given to anyone, regardless of their blood type.
Choice C is wrong because type AB blood can receive more than just two of the blood types. Type AB blood can receive both A and B blood, as well as O and AB blood.
Choice D is wrong because type AB blood can receive more than just one of the blood types. Type AB blood can receive any blood type without problems.
Normal ranges for blood types vary by population, but generally, type O is the most common, followed by type A, type B, and type AB.