Answer:
pathogens is the correct answer.
Step-by-step explanation:
A pathogen is an infectious agent that causes diseases.
Examples of pathogens that cause disease are bacteria, protozoa, fungi, helminths, viruses, and protozoa.
when pathogens enter the host body through nose, eyes, bites, mouth and it destructs the host immune system that causes infectious disease.
diseases caused by infectious agents are cholera, dysentery, tuberculosis, bubonic plague, typhoid, and pneumonia, etc.