You are presented with the question "Microorganisms cause what inside of the cells of living organisms?" and the following answer choices: 
- heat
 - harm them
 - health
 - worms
 - illness
 - resistance
 - Allergies
 - antibodies

Now knowing that viruses infect and live inside the cells of living organisms and an infection is an illness caused by the invasion of a virus or microorganism, choose the best answer.


 

     illness    