A.alistoffilesthatrequireabackupwithinthreedays
B.alistoffilesrequiringmorethan3daysofarchivelogstoapply
C.alistoffilesthatRMANrecommendsbebackeduponlyonceineverythreedays，basedonlowvolatility
D.alistoffilesforwhichabackuphasalreadybeenperformedinthelastthreedaysandwhichisrequiredtobebackedupagainbasedonthehighnumberoftransactionsperformedonthem
正确答案：参考A
