单项选择题
A.AES
B.3DES
C.DES
D.Diffie-Hellman
单项选择题 Which item is the correct matching relationships associated with IKE Phase？（）
单项选择题 Forthefollowingattempts，whichoneistoensurethatnooneemployeebecomesapervasivesecuritythreat，thatdatacanberecoveredfrombackups，andthatinformationsystemchangesdonotcompromiseasystem’ssecurity？（）
单项选择题 WhichoneofthefollowingcommandscanbeusedtoenableAAAauthenticationtodetermineifausercanaccesstheprivilegecommandlevel？（）