Final answer:
The term used to describe the total number of existing cases of a specific condition with respect to the entire population, represented as a percentage of the population, is b) prevalence rate.
Step-by-step explanation:
The term used to describe the total number of existing cases of a specific condition with respect to the entire population, represented as a percentage of the population, is prevalence rate (option b).
Prevalence rate is a measure that indicates the overall health of a population over time.
It includes both new and existing cases of a disease.
Incidence rate (option a) is a measure of the number of new cases of a disease during a specific time period.
Mortality rate (option c) is a measure of the number of deaths in a population during a given time period.