Q: What occurs when the immune system is not working properly?


Read this paragraph and choose the correct option from the provided answers:

Immunodeficiency occurs when the immune system is not working properly. As a result, it cannot fight off pathogens that a normal immune system would be able to resist. Rarely, the problem is caused by a defective gene. More often, it is acquired during a person’s lifetime. Immunodeficiency may occur for a variety of reasons:.

 Choices:

- allergy

- cancer

- anemia

- immunodeficiency


A:
immunodeficiency