The answer is D.) Lymphocytes. The lymphocyte is a type of white blood cell that has an auto-immune system. When a person’s immune system detects a substance such as food, animal fur or dust as harmful to one’s body, it causes an allergy attack. Lymphocyte fights these off to remove them from the body by producing more lymphocytes to bind the allergens.
They do a great job in keeping the human’s systems free from invaders and keeping the body healthy. A person’s health might be in a great danger when there is no or a low number of lymphocyte cells as there is nothing to fight the harmful substances that are trying to invade the body.