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
Most common detion used in social medicine is- 
Select and explain. 
A. Mean, B. Range, C. Variance, D. Standard detion
D: Standard detion
Answer: D: Standard detion 
Explanation: Ans. is 'd' i.e., Standard detion "Standard detion is most common and generally most appropriate measure of dispersion (variation)".