Question

ability of the adaptive immune response to mount a stronger and faster immune response upon re - exposure to a pathogen...
barrier defenses
immunological memory
chemokine

Explanation:

Immunological memory allows the adaptive immune system to recognize and respond more strongly and quickly to a previously - encountered pathogen. Barrier defenses are the first - line physical and chemical barriers against pathogens, and chemokines are signaling proteins that attract immune cells.

Answer:

Immunological memory