What is the explanation for this behavior?

A storage architect is evaluating the performance of a PowerMax array during business hours. They want to know how much extra load the PowerMax can handle without significant performance degradation. The Workload Planner is used to identify the hot spots during the recurring backup windows.

Between 9:30 PM and 1:30 AM and between 3:15 AM and 5:30 AM, backups are causing the PowerMax to exceed the best practice recommendation. The Recurring System Data Exclusion Periods chart is used to filter out these hot spots. After running this workload planning for a few weeks, they notice that the selection of records they previously made are showing different numbers than when they started viewing the report, several weeks ago.

What is the explanation for this behavior?
A . After a week the data of each time slot is refreshed with new data
B . After two weeks the 84 data points are filled up and the report resets to default
C . The average of the viewed window has dropped below the best practice
D . After two weeks the data of each time slot is refreshed with new data

Answer: D