Antigens are molecules that the immune system recognizes as foreign to the body, and children are born with an immature immune, or defense, system. Given these facts, what are molecules that the defense system recognizes as foreign to the body among the following options:
- Allergies
 - lungs
 - antigens
 - bacteria
 - parasites
 - atoms
 - red blood cells
 - acetic acid


 

   antigens      