You are an administrator of a single Active Directory forest that contains one domain. All servers run Windows Server 2003. A server named VPN1 is configured with Routing and Remote Access. VPN1 is configured to allow only inbound VPN connections that use L2TP. You assign the Server （Request Security） IPSec policy on VPN1. You configure the policy to use Kerberos and certificates for authentication.From a Windows XP Professional computer named Client1， which does not belong to the domain， you attempt to establish a VPN connection to VPN1 and receive the error message shown in the exhibit. （Click the Exhibit button.） You verify that the VPN ports on VPN1 are not being blocked by any intermediate devices.  You need to configure Client1 to allow it to establish a VPN connection to VPN1.   What should you do？（）

• A、Assign the Client （Respond Only） IPSec policy.
• B、Assign the Server （Request Security） IPSec policy.
• C、Install a valid IPSec certificate in the local machine store.
• D、Configure the VPN connection so that only L2TP IPSec VPN is enabled.