Disease-causing microbes have a negative impact on the body, and microbes are microscopic, single-celled organisms without a nucleus. Given these facts, what has a negative impact on the body among the following options:
- photons
 - exposure to cold
 - abundant food
 - influenza orthomyxoviruses
 - disease-causing organisms
 - smallest agents of disease
 - rocks
 - a tree falling


 

     disease-causing organisms    