**Core Concept**
Prevention in medicine is classified into three types: primary, secondary, and tertiary. Primary prevention aims to prevent the occurrence of a disease, secondary prevention focuses on early detection and intervention to prevent the progression of a disease, and tertiary prevention aims to reduce the impact of an established disease on a person's quality of life.

**Why the Correct Answer is Right**
Screening of a disease is an example of secondary prevention. It involves the use of a test or examination to detect a disease in its early stages, before symptoms appear, in order to prevent or delay the onset of the disease. Screening tests are designed to identify individuals who are at risk of developing a disease, allowing for early intervention and potentially preventing the progression of the disease.

**Why Each Wrong Option is Incorrect**
**Option A:** Primary prevention is incorrect because it involves measures to prevent the occurrence of a disease in the first place, such as vaccination or healthy lifestyle choices.
**Option B:** Tertiary prevention is incorrect because it involves measures to manage and prevent the complications of a disease that has already been established.
**Option C:** This option is not provided, so we cannot evaluate it.

**Clinical Pearl / High-Yield Fact**
Screening tests can be either universal or targeted, depending on the population being screened and the characteristics of the disease being screened for. Universal screening involves screening the entire population, while targeted screening involves screening only those at high risk of developing the disease.

**Correct Answer: C. Secondary prevention.