Which statement is true about the UNDO_RETENTION parameter when retention guarantee is not enabled?

A.
It is the time period after which the committed undo data would be transferred to a temporary tablespace.

B.
It is the time period after which the undo data becomes obsolete.

C.
It is the minimum time period up to which the committed undo data would be retained if free undo space is available.

D.
It is the time period after which the undo data is transferred to the Flash Recovery Area to provide read consistency.