## Core Concept
The question revolves around the most appropriate method for mass screening of tuberculosis (TB), focusing on the detection methods used for identifying TB cases in a large population. The primary goal of mass screening for TB is to quickly and accurately identify individuals with active TB disease to provide timely treatment and prevent further transmission.

## Why the Correct Answer is Right
The correct answer, **Sputum Smear Microscopy**, is considered the method of choice for mass screening of tuberculosis due to its simplicity, cost-effectiveness, and rapid turnaround time. This method involves examining a sputum sample under a microscope for the presence of acid-fast bacilli (AFB), which are indicative of TB infection. Sputum smear microscopy is widely used in resource-limited settings because it is relatively inexpensive and can be performed with minimal laboratory equipment. It has a reasonable sensitivity and specificity for detecting pulmonary TB, especially in smear-positive cases, which are the most infectious.

## Why Each Wrong Option is Incorrect
- **Option A:** While **Nucleic Acid Amplification Tests (NAATs)** offer high sensitivity and specificity for TB detection, they are more expensive and require sophisticated laboratory infrastructure, making them less suitable for mass screening in resource-limited settings.
- **Option B:** **Chest Radiography** can be useful for identifying pulmonary abnormalities suggestive of TB but requires more resources (X-ray machines and radiologists) and does not provide a definitive diagnosis. It is often used as a secondary tool after sputum smear microscopy.
- **Option D:** **Culture for Mycobacterium tuberculosis** is the gold standard for diagnosing TB but is not practical for mass screening due to its slow turnaround time (weeks), high cost, and requirement for sophisticated laboratory facilities.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the World Health Organization (WHO) recommends sputum smear microscopy as the primary method for diagnosing pulmonary TB in low- and middle-income countries due to its feasibility and cost-effectiveness. However, with advancements in technology, the use of rapid diagnostic tests like GeneXpert MTB/RIF is becoming more widespread, offering a quicker and more sensitive diagnosis.

## Correct Answer Line
**Correct Answer: C. Sputum Smear Microscopy**