You are presented with the question "Immunodeficiency occurs when the immune system is what?" and the following answer choices: 
- dangerous
 - homogenous
 - healthy
 - broken down
 - reduce
 - perfect
 - It decreases
 - functioning

Now knowing that immunodeficiency occurs when the immune system is not working properly and work items are broken down by year of effort, choose the best answer.


 

    broken down     