## **Core Concept**
The question tests the understanding of levels of prevention in public health, specifically the classification of prevention strategies into primary, secondary, tertiary, and primordial prevention. Screening of a disease falls under a specific level of prevention aimed at early detection.

## **Why the Correct Answer is Right**
The correct answer, **Secondary Prevention**, involves measures aimed at detecting and treating problems early before the disease becomes more serious. Screening for diseases is a classic example of secondary prevention because it seeks to identify diseases in their earliest stages, often before symptoms appear, thereby enabling early intervention.

## **Why Each Wrong Option is Incorrect**
- **Option A: Primordial Prevention** is incorrect because it involves actions taken to avoid the emergence of risk factors in countries or population groups where they have not yet appeared. Screening does not fit here as it is not about preventing the emergence of risk factors but about early detection of disease.
- **Option B: Primary Prevention** is incorrect because it involves interventions aimed at preventing the disease before it occurs, such as vaccination, changing lifestyle habits, or using chemoprophylaxis. While it is a level of prevention, it does not involve screening.
- **Option D: Tertiary Prevention** is incorrect because it focuses on reducing the impact of an ongoing illness or injury that has lasting effects. This includes efforts to prevent deterioration, complications, and disability, and to help individuals manage chronic conditions. Screening for diseases does not fall into this category.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the levels of prevention are hierarchical and sequential: **Primordial Prevention** aims to prevent risk factors, **Primary Prevention** aims to prevent disease, **Secondary Prevention** aims to detect disease early (screening), and **Tertiary Prevention** aims to manage disease and prevent complications. Understanding these distinctions is crucial for public health strategies and clinical practice.

## **Correct Answer: B. Secondary Prevention**