This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
Example for multipurpose screening. 
Select and explain. 
A. Chest X-ray for Tb on large population, B. Annual health check ups, C. Pap smear in elderly females, D. Eye check up in school children
B: Annual health check ups
Answer: B: Annual health check ups 
Explanation: None