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
Best statistical data diagram to depict incidence change over a period of tissue is 
Select and explain. 
A. Pie char, B. Histogram, C. Scatter diagram, D. Line diagram
D: Line diagram
Answer: D: Line diagram 
Explanation: None