## **Core Concept**
The national T control programme, likely referring to tuberculosis (TB) control programs, involves several key strategies to manage and prevent the spread of TB. These strategies include vaccination, identification and treatment of active cases, and measures to prevent transmission.

## **Why the Correct Answer is Right**
The correct answer, which is not explicitly listed but implied through the process of elimination, relates to understanding the standard components of TB control programs. These typically include:
- **BCG vaccination**: To prevent severe forms of TB in children.
- **Treatment of sputum-positive cases**: To cure individuals with active TB and prevent transmission.
- **Isolation of sputum-positive cases**: To reduce the risk of transmission to others.

## **Why Each Wrong Option is Incorrect**
- **Option B: Treatment of contacts**: While treating contacts, especially those with latent TB infection, is an important strategy in TB control, it is not universally applied as a primary step like the others listed. Contacts are often given preventive therapy if they are at high risk, but this is not as universally applied or emphasized as the other measures for general control.
- The other options (a, c, d) are all critical and commonly recognized steps in TB control.

## **Clinical Pearl / High-Yield Fact**
A key aspect of TB control is the **Directly Observed Treatment, Short-Course (DOTS)** strategy, which is a form of directly observed therapy. This approach ensures adherence to treatment and is a cornerstone of TB control programs worldwide.

## **Correct Answer:** B. Treatment of contacts