which response is correct?

In an Active Session History report, which response is correct?

A.
60 minutes of ASH data can be held in memory, so only 1 hour can be reported.

B.
60 minutes of ASH data can be held in memory, but more than 1 hour can be reported.

C.
ASH data is available 24 hoursbecause AWR snapshots refresh every night.

D.
As ASH data is flushed every 60 seconds, you need to set up a snapshot withDBA_JOBSfor what you want to keep.