Fact 1: Active immunity results when an immune response to a pathogen produces memory cells.

Fact 2: Pathogens are simply a variety of diseases which kill insects.

Given the two facts above, answer the question "What prevents insects from being killed?" with the following options: 
- Fly swatter
 - Active immunity
 - Exfoliation
 - a cuticle
 - food
 - bugs
 - rays or beams
 - resistance


 

  Active immunity       