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
The following diagram is drawn to study: 
Select and explain. 
A. Trend of a variable over a period of time, B. Frequency of occurrence of events, C. Mean & median values of the given data, D. Relationship between two given variables
D: Relationship between two given variables
Answer: D: Relationship between two given variables 
Explanation: SCATTER DIAGRAM

Also known as ‘Correlation diagram’ or ‘Dot diagram’.
Is used to depict ‘correlation (relationship) between 2 quantitative variables’.
‘Vertical axis in scatter diagram: should be the dependent or the outcome variable.
In a scatter diagram, 2 imaginary lines are drawn along the distribution of dots/scatter.