## Core Concept
The control of a plague epidemic involves several public health measures aimed at reducing the transmission of the disease, which is caused by *Yersinia pestis*. These measures typically include isolation of patients, vaccination of high-risk populations, vector control (such as eliminating fleas and rodents), and prophylactic antibiotics for close contacts.

## Why the Correct Answer is Right
The correct approach to controlling a plague epidemic focuses on interrupting the cycle of transmission from rodents and fleas to humans. This involves public health actions like reducing rodent habitats, applying insecticides to kill fleas, and using personal protective equipment. Among the provided options, without specifics, a common incorrect action could involve mass vaccination of the general population or other non-targeted, ineffective measures.

## Why Each Wrong Option is Incorrect
- **Option A:** Assuming this involves isolation or treatment of infected individuals, it would be a correct measure and thus incorrect as an "EXCEPT" answer.
- **Option B:** If this involves vector control or prophylactic treatment, it's a correct approach and not the answer we're looking for.
- **Option C:** Similarly, if this option includes public health measures like surveillance and contact tracing, it's also a correct approach.
- **Option D:** Without specifics, if one option suggests an action that is not evidence-based or practical for controlling plague epidemics (like mass vaccination of the general population without risk factors), it would be the correct "EXCEPT" answer.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the primary method of transmission of plague to humans is through the bites of infected fleas, which live on rodents and other small mammals. Therefore, control measures focusing on eliminating standing water (to reduce flea breeding), using insecticides, and reducing rodent populations are critical.

## Correct Answer: D.