This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2019, Subject name: Social & Preventive Medicine
What happens to minimum sample size when range of allowable error is doubled? 
Select and explain. 
A. Reduced to 1/2, B. Reduced to 1/4, C. Reduced to 1/16, D. Sample size does not depend on acceptable error
B: Reduced to 1/4
Answer: B: Reduced to 1/4 
Explanation: Sample size = 4 Pq / L2 ( permissible error )Sample size a 1/ (error)2= 1/ (2E)2= 1/4