Why does the Adaptive Immune System keep a memory of the pathogens they fight off, but Innate System does not?

A. Adaptive immunity is present at birth and needs to keep a memory of these pathogens over time, but Innate immunity is temporary so it does not a memory of pathogens.

B. Adaptive immunity is short lived, it keeps a memory of pathogens for future reference, whereas Innate immunity is present at birth so it does not need to keep a memory.

C. Innate immunity does not fight off pathogens so it cannot keep a record, while Adaptive immunity only fights off pathogens, therefore needing to keep a memory of them.