Answer:Option B
The memory response is due to long lived cells that can respond rapidly to second exposure.
Explanation:
Immunological memory is the ability of the immune system to quickly identify and remember an antigen from a pathogen that the body has encountered before and initiate a faster immunological response upon a reencounter with the particular antigen. This dependents on colonial selection.. The memory cells have a long life span and can remain in the body for a long time. When it encounter the antigen its previously encountered for the second time, they mobilize quickly and become plasma cells, these secrets a lot of antibodies and cause a stronger reaction to defend against such antigen in a short time.