The Best Evidence Supporting the Concept of Immunological Memory Is

Multiple Choice

The best evidence supporting the concept of immunological memory is:

A) The increased numbers of antigen receptors expressed by lymphocytes after primary exposure to an antigen
B) The increased levels of cytokines made by lymphocytes after primary exposure to an antigen
C) The increased rapidity and magnitude of the secondary response to the same antigen
D) The increased swelling of lymph nodes during the secondary response to the same antigen
E) The long lifespan of vertebrates, which would be impossible without immunological memory