单项选择题
For the following items ，which one can be used to authenticate the IPsec peers during IKE Phase 1？（）
A.pre-shared key B.integrity check value C.XAUTH D.Diffie-Hellman Nonce
单项选择题 Which description is correct based on the exhibit and partial configuration？（）
单项选择题 Inabrute-forceattack，whatpercentageofthekeyspacemustanattackergenerallysearchthroughuntilheorshefindsthekeythatdecryptsthedata？（）
