## Core Concept
Proportional mortality rate (PMR) is a measure used in epidemiology to describe the proportion of total deaths in a population that are attributable to a specific cause. It essentially quantifies the burden of a particular disease or condition on mortality within a population.

## Why the Correct Answer is Right
The correct formula for proportional mortality rate is:
[ PMR = frac{text{Number of deaths from a specific cause}}{text{Total number of deaths from all causes}} times 100 ]
This measure helps in understanding the impact of different causes of death within a population and is often expressed as a percentage. It does not take into account the population at risk, making it different from rates like incidence or mortality rates.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is incorrect because it seems to represent a formula for a rate or ratio but lacks specificity regarding what it measures or the context of proportional mortality.
- **Option B:** This option does not provide a clear or correct formula for proportional mortality rate. It might confuse with other epidemiological measures.
- **Option D:** Similarly, this option does not accurately represent the proportional mortality rate. It might be related to other types of epidemiological calculations.

## Clinical Pearl / High-Yield Fact
A key point to remember is that proportional mortality rate helps in prioritizing public health interventions by highlighting causes of death that are most prevalent. For instance, in areas with high PMR for cardiovascular diseases, interventions targeting heart health might be particularly crucial.

## Correct Answer: C.