Final answer:
A point-source epidemic arises from a single exposure event affecting multiple individuals, typically acting over a period shorter than the pathogen's incubation period.
Step-by-step explanation:
A point-source epidemic occurs due to a single exposure of a group of people. The correct option is c) point-source. This type of epidemic is characterized by all infections originating from a single, common source that operates for a short time period, typically less than the incubation period of the pathogen. An example would be an outbreak resulting from a group of people consuming contaminated food at a picnic. This contrasts with a propagated spread, which results from direct or indirect person-to-person contact, and does not have a single source for infections.
A point source epidemic occurs due to a single exposure of a group of people. In this type of epidemic, the common source operates for a short time period, which is less than the incubation period of the pathogen. An example of a point source epidemic is a single contaminated potato salad at a group picnic. Point source spread typically leads to localized outbreaks of short duration.