This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Normal Distribution, Skewed Distributions, Subject name: Social & Preventive Medicine
The mean of the 25 plasma volumes is 12.5 litres. Standard detion is 0.25. Calculate Variance:- 
Select and explain. 
A. 0.0625, B. 0.625, C. 6.25, D. 625
A: 0.0625
Answer: A: 0.0625 
Explanation: - Standard detion = square root of variance Variance = (S.D X S.D) - Given SD = 0.25 - Thus, Variance = 0.25 x 0.25 = 0.0625