**Core Concept**
Prevention of disease by immunization is a crucial aspect of public health, involving the use of vaccines to induce immunity against infectious diseases. This approach is grounded in the concept of immunological memory, where the body's immune system retains a "memory" of the pathogen, enabling it to mount a rapid and effective response upon subsequent exposure.

**Why the Correct Answer is Right**
Immunization falls under the category of specific preventive measures, which involve targeting a specific disease or condition to prevent its occurrence. Vaccines work by stimulating the production of antibodies and activating immune cells, such as T-cells and B-cells, to recognize and eliminate pathogens. The correct answer is linked to the concept of specific prevention, where the aim is to prevent a specific disease through the use of vaccines.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the category under which immunization falls. While it may be related to prevention, it does not specifically address the use of vaccines or immunization.
**Option B:** This option is incorrect because it does not accurately describe the category under which immunization falls. While it may be related to public health, it does not specifically address the use of vaccines or immunization.
**Option C:** This option is incorrect because it does not accurately describe the category under which immunization falls. While it may be related to disease prevention, it does not specifically address the use of vaccines or immunization.

**Clinical Pearl / High-Yield Fact**
Immunization is a highly effective and safe method of preventing infectious diseases, with many vaccines having been shown to reduce the risk of disease by 90% or more. The World Health Organization (WHO) recommends the use of vaccines as a key component of public health strategies to prevent and control infectious diseases.

**Correct Answer:** C.