Long-Term Immunity to Diseases Such as Measles Occurs Because

Long-term immunity to diseases such as measles occurs because

A) memory mast cells produce antibodies in response to pathogens entering the body.
B) plasma cells remain in the immune system to protect the body.
C) memory B cells are produced in response to specific pathogens.
D) neutrophils remain in the blood to phagocytize any new measles pathogens.
E) helper T cells continue to produce cytokines indefinitely.