**Core Concept**
A point source epidemic is a type of outbreak that occurs when a group of people are exposed to a common source of infection at the same time, such as contaminated food or water, leading to a sudden increase in cases. This type of outbreak is typically characterized by a sharp peak in cases, followed by a decline as the source of infection is removed.

**Why the Correct Answer is Right**
The correct answer is related to the definition and characteristics of a point source epidemic. In a point source epidemic, the exposure to the infectious agent occurs at a single point in time, and the cases are clustered together in time. This type of epidemic is often caused by a common source of infection, such as contaminated food or water, that is consumed by a group of people.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a characteristic that is unique to point source epidemics. While it is true that point source epidemics often have a single peak in cases, this is not a defining feature of this type of epidemic.

**Option B:** This option is incorrect because it describes a characteristic of a propagated epidemic, not a point source epidemic. Propagated epidemics occur when the infection is spread from person to person over time.

**Option C:** This option is incorrect because it is a true statement about point source epidemics. In a point source epidemic, the cases are often clustered together in time and space, and the exposure to the infectious agent occurs at a single point in time.

**Clinical Pearl / High-Yield Fact**
A key feature of point source epidemics is that they often have a distinct "attack rate" or proportion of exposed individuals who become infected, which can be used to estimate the size of the outbreak.

**Correct Answer:** C.