Your company has a main office and 15 branch offices. The company has a single Active Directory domain. All servers run Windows Server 2008. You need to ensure that the VPN connections between the main office and the branch offices meet the following requirements：All data must be encrypted by using end-to-end encryption. The VPN connection must use computer-level authentication User names and passwords cannot be used for authentication. What should you do？（）

• A、 Configure an IPsec connection to use tunnel mode and preshared key authentication.
• B、 Configure a PPTP connection to use version 2 of the MS-CHAP v2 authentication.
• C、 Configure a L2TP/IPsec connection to use the EAP-TLS authentication
• D、 Configure a L2TP/IPsec connection to use version 2 of the MS-CHAP v2 authentication.