This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
Most crucial pa of tuberculosis control programme is - 
Select and explain. 
A. Contact tracing, B. BCG vaccination, C. Treatment of sputom positive cases, D. Treatment of X-ray positive cases
C: Treatment of sputom positive cases
Answer: C: Treatment of sputom positive cases 
Explanation: Park&;s Textbook of Preventive and Social Medicine 23rd edition Page no: 182 Sputum smear examination by direct microscopy is now considered the method of choice. The reliability, cheapness and ease of direct microscopic examination have made it number one case finding method all over the world. It enables us to discover the epidemology most impoant cases of pulmonary tuberculosis