Which statements are true regarding the system-defined moving window baseline in Oracle Database 11g?（）

• A、It does not allow you to change the moving window size.
• B、Adaptive threshold functionalities use it by default to compute statistics.
• C、It is created by default with the window size being equal to the AWR retention time.
• D、It is created when the first snapshot is collected by the Automatic Workload Repository (AWR).