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

Fact 2: If the parasite causes harm, it is a pathogen.

Given the two facts above, answer the question "What creates active immunity from a parasite?" with the following options: 
- Cooking
 - memory cells
 - alpacas
 - peachleaf willow
 - Allergies
 - mammals
 - an organism's body
 - animals


 

  memory cells       