Final answer:
c. Infectious diseases are communicable diseases caused by pathogens, while noninfectious diseases are not caused by pathogens and cannot be passed from person to person.
Step-by-step explanation:
An infectious disease is a type of communicable disease that can be transmitted from person to person or from animals to humans. Examples of infectious diseases include pertussis (whooping cough) and sexually transmitted infections like HIV and herpes. These diseases are caused by pathogens such as bacteria, viruses, or fungi. On the other hand, noninfectious diseases are not caused by pathogens and cannot be passed from person to person. They are generally caused by genetic or environmental factors, such as cystic fibrosis or heart disease.