The Situation Described in This Case Study Is an Example

The situation described in this case study is an example of a(n)

A) propagated epidemic, because one student became ill, followed by others over several days.
B) common-source epidemic, because several students became ill in the same time frame.
C) propagated epidemic, because several students became ill in the same time frame.
D) epidemic, because one student became ill and then spread the causative organism to many others.
E) cohort study, because there was a group of students all affected by the same pathogen.