Antigens are molecules that the immune system recognizes as foreign to the body, and antibodies are produced to fight antigens. Given these facts, what happens when the immune system recognizes a foreign substance among the following options:
- an area swollen with pus
 - The immune system fails
 - irradiation
 - Bacteria dies
 - Antibodies are formed
 - major threat to health
 - Something that causes allergies
 - Viruses reproduce


 

     Antibodies are formed    