**Core Concept**
The Integrated Disease Surveillance Programme (IDSP) is a national programme aimed at strengthening the surveillance and response to disease outbreaks. It focuses on both communicable and non-communicable diseases. For non-communicable diseases, the programme emphasizes the importance of monitoring and managing risk factors.

**Why the Correct Answer is Right**
The correct answer is **C. Risk Factor Surveillance**. This approach involves monitoring and managing risk factors associated with non-communicable diseases, such as hypertension, diabetes, and cardiovascular disease. Risk factor surveillance helps in identifying the population at risk, understanding the distribution of risk factors, and planning targeted interventions. This approach is essential for preventing and managing non-communicable diseases.

**Why Each Wrong Option is Incorrect**
**Option A:** is incorrect because **Traditional Disease Reporting** focuses on reporting of disease cases, which is more relevant to communicable diseases. While traditional disease reporting is essential, it is not the primary approach for non-communicable diseases.

**Option B:** is incorrect because **Epidemiological Investigation** is a method used to investigate the causes and distribution of diseases, but it is not a specific approach for non-communicable diseases.

**Clinical Pearl / High-Yield Fact**
Risk factor surveillance is a critical component of disease prevention and management. It helps in identifying high-risk populations and planning targeted interventions, which can lead to significant reductions in morbidity and mortality from non-communicable diseases.

**Correct Answer:** C. Risk Factor Surveillance