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: Dental
Measures of dispersion variability: 
Select and explain. 
A. Variance, B. Standard deviation, C. Range, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Measures of dispersion variability:

Variance
Standard deviation
Range
Interquartile range