**Core Concept**
Primary prevention aims to prevent the occurrence of a disease or injury before it happens. It involves measures that prevent the onset of a disease or condition, such as health promotion, health education, and specific protective measures.

**Why the Correct Answer is Right**
Self breast examination (SBE) is a form of secondary prevention, not primary prevention. Secondary prevention focuses on early detection and treatment of a disease, whereas primary prevention aims to prevent the disease from occurring in the first place. SBE is a screening technique used to detect breast cancer or abnormalities at an early stage, which is a secondary prevention measure.

**Why Each Wrong Option is Incorrect**
**Option A:** Marriage counselling is an example of a primary prevention measure as it helps prevent relationship problems and promotes healthy relationships, thereby reducing the risk of mental health issues and other social problems.

**Option B:** Health education is a primary prevention measure that aims to educate individuals about healthy behaviors, disease prevention, and risk factor reduction, thereby preventing the occurrence of diseases.

**Option D:** Health promotion is a primary prevention measure that aims to promote healthy behaviors, lifestyles, and environments to prevent the onset of diseases and promote overall well-being.

**Clinical Pearl / High-Yield Fact**
Primary prevention measures are often the most cost-effective and efficient way to prevent diseases, as they aim to prevent the disease from occurring in the first place, rather than treating it after it has occurred.

**✓ Correct Answer: C. Self breast examination**