## Core Concept
The case fatality rate is a measure used in epidemiology to describe the severity of a disease. It is defined as the proportion of deaths within a designated population of people with a particular condition over the course of the disease. This rate is often expressed as a percentage and helps in understanding the lethality or fatality of a disease.

## Why the Correct Answer is Right
The correct answer, **C. Number of deaths due to a specific disease/Number of people diagnosed with the same disease × 100**, accurately represents the formula for calculating the case fatality rate. This formula essentially looks at the number of individuals who die from a specific disease and divides it by the number of individuals diagnosed with that same disease, then multiplies by 100 to get a percentage. This calculation provides insight into the severity or deadliness of a disease.

## Why Each Wrong Option is Incorrect
- **Option A: Number of deaths due to all causes/Number of population × 100**: This option describes the crude death rate, not the case fatality rate. It calculates the total number of deaths from all causes in a population, which is not specific to a particular disease.
- **Option B: Number of new cases of a disease/Number of population at risk × 100**: This option refers to the incidence rate of a disease, which measures the number of new cases that develop in a specified time period among a population at risk.
- **Option D: Number of deaths due to a specific disease/Number of population × 100**: This option seems to calculate a rate of death due to a specific disease within a population but does not take into account those specifically diagnosed with the disease, thus not representing the case fatality rate.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the case fatality rate is a measure of disease severity and is often used for diseases with a high mortality rate, such as Ebola or Rabies. It does not account for the duration of the disease and can vary significantly depending on factors like healthcare quality and the population affected.

## Correct Answer: C. Number of deaths due to a specific disease/Number of people diagnosed with the same disease × 100