Marlene demonstrates a classic primary immune response as, with the help of antibiotics, she recovers from her infection.

How will Marlene's immune system react if she encounters this same pathogen again?

a. Memory B cells will undergo rapid proliferation.
b. Memory B cells will begin immediate antibody secretion.
c. Marlene will be unaware that the pathogen has invaded her system since this rapid secondary response will prevent illness from occurring.
d. Memory B cells will undergo rapid proliferation, begin immediate antibody secretion, and Marlene will be unaware that the pathogen has invaded her system.
e. Memory B cells will undergo rapid proliferation, begin immediate antibody secretion, and Marlene will be unaware that the pathogen has invaded her system, but she will need to continue a prophylactic antibiotic course.

Memory B cells hold the key to Marlene's rapid immune response upon re-encountering the same pathogen. These cells will undergo rapid proliferation and immediate antibody secretion, allowing for a heightened secondary response that can prevent severe illness. The memory cells remember the antigen, leading to a more efficient defense mechanism the next time around.

Learn more about Immune system response here:

https://brainly.com/question/50823677