Question

a person who has allergies has a compromised immune system because the bodys immune system
attacks its healthy cells.
overreacts to an antigen.
steals nutrients from healthy cells.
responds to mutagens.

Explanation:

Allergies occur when the immune system overreacts to an antigen (allergen). Autoimmune diseases involve attacking healthy cells. Nutrient - stealing is not a mechanism of allergies. Mutagen response is related to genetic changes, not allergies.

Answer:

overreacts to an antigen.