**Core Concept**
Prevalence is a measure of the total number of cases of a disease present in a population at a specific point in time or over a specified period. It is an important indicator of the burden of disease in a community.

**Why the Correct Answer is Right**
The prevalence of a disease is indeed influenced by both incidence and duration. Incidence refers to the number of new cases of a disease that occur within a specified period, while duration refers to the length of time individuals remain affected by the disease. When the incidence is high and the duration is long, the prevalence of the disease increases, as more individuals are likely to be affected for a longer period. Conversely, if the incidence is low or the duration is short, the prevalence will be lower.

**Why Each Wrong Option is Incorrect**
* **Option A:** Incidence alone does not determine prevalence, as it only accounts for new cases and does not consider the duration of the disease.
* **Option B:** Duration alone does not determine prevalence, as it only accounts for the length of time individuals are affected and does not consider the incidence of new cases.
* **Option D:** This option is incorrect because both incidence and duration are indeed factors that influence the prevalence of a disease.

**Clinical Pearl / High-Yield Fact**
When evaluating the prevalence of a disease, it is essential to consider both the incidence and duration of the disease, as well as other factors such as population size and demographics. This will provide a more accurate understanding of the disease burden in a community.

✓ Correct Answer: C. Both of the above