**Core Concept**
Prevention of breast cancer involves strategies to reduce the risk of developing this disease. The levels of prevention are primary, secondary, and tertiary prevention. Primary prevention aims to prevent the disease before it occurs, while secondary prevention tries to detect and treat the disease early to prevent progression.

**Why the Correct Answer is Right**
The best level of prevention for breast cancer is primary prevention, which involves reducing the risk factors that contribute to the development of breast cancer. This can be achieved through a combination of lifestyle modifications, such as maintaining a healthy weight, engaging in regular physical activity, and avoiding excessive alcohol consumption. Additionally, certain medications, such as tamoxifen and raloxifene, have been shown to reduce the risk of breast cancer in high-risk individuals.

**Why Each Wrong Option is Incorrect**
**Option A:** Secondary prevention is not the best level of prevention for breast cancer because it focuses on early detection and treatment, rather than preventing the disease from occurring in the first place.
**Option B:** Tertiary prevention is not relevant to breast cancer prevention, as it focuses on managing and preventing complications in patients who already have the disease.
**Option C:** Primary prevention is the correct answer, as it involves reducing risk factors and preventing the disease from occurring in the first place.

**Clinical Pearl / High-Yield Fact**
The risk of breast cancer can be reduced by 50% in high-risk individuals through the use of medications such as tamoxifen and raloxifene. These medications work by blocking estrogen receptors in the breast tissue, which can help to prevent the growth of cancer cells.

**Correct Answer: C. Primary prevention**