Which level of prevention is applicable in a population without any risk factor-
**Core Concept**
The underlying principle being tested is the concept of **levels of prevention** in public health, which includes primary, secondary, and tertiary prevention. Primary prevention aims to prevent disease before it occurs, and it can be further divided into health promotion and specific protection.
**Why the Correct Answer is Right**
Primary prevention is applicable in a population without any risk factor, as it aims to prevent the onset of disease by promoting general health and well-being. This can be achieved through **health education**, **vaccination**, and **lifestyle modifications**. Since the population does not have any risk factors, the focus is on maintaining their health and preventing the occurrence of disease.
**Why Each Wrong Option is Incorrect**
**Option A:** Is incorrect because it is not the level of prevention that is applicable in this scenario.
**Option B:** Is incorrect because secondary prevention is applicable when there are risk factors or early disease detection is possible.
**Option D:** Is incorrect because tertiary prevention is applicable when the disease is already established.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that primary prevention is the most cost-effective level of prevention, as it reduces the burden of disease on the healthcare system.
**Correct Answer:** A. Primary prevention.