Final answer:
Walking pneumonia is caused by Mycoplasma pneumoniae bacteria. College students have the highest incidence of walking pneumonia.
Step-by-step explanation:
Walking pneumonia, also known as primary atypical pneumonia, is caused by the bacteria Mycoplasma pneumoniae. It is a common infection in crowded environments like college campuses and military bases. The highest incidence of walking pneumonia is observed in the age group of young adults, particularly college students.