Abreathing mask is used for keeping harmful particles from entering the respiratory system, and allergies are a reaction of the immune system to harmful particles in the air. Given these facts, what can prevent an allergic reaction among the following options:
- chemical messengers
 - prolactin release
 - with their fur
 - sweating
 - Breathing mask
 - deoxyribonucleic acid
 - Cooking
 - hormones


 

     Breathing mask    