Why Are the Second and Subsequent Responses to Antigen Exposure

Multiple Choice

Why are the second and subsequent responses to antigen exposure faster than the initial response?

A) The antibodies of the secondary response are more efficient.
B) The antibodies of the secondary response are less efficient.
C) After the initial exposure, memory cells are present; they respond more quickly upon a second exposure to the antigen.
D) After the initial exposure, the memory cells respond more slowly, as the pool of available cells has been diminished.
E) Pathogens are generally weaker with the second exposure.