Your network consists of an Active Directory domain and a DirectAccess infrastructure. You install Windows 7 on a new portable computer and join the computer to the domain. You need to ensure that the computer can establish DirectAccess connections. What should you do?

A.
Install a computer certificate.

B.
Create a new network connection.

C.
Enable the Network Discovery firewall exception.

D.
Add the computer account to the Network Configuration Operators group.

Explanation:
Certificates
The DirectAccess IPsec session is established when the client running Windows 7 and the DirectAccess server authenticate with each other using computer certificates. DirectAccess supports only certificate-based authentication.
DirectAccess Client Configuration
Clients receive their DirectAccess configuration through Group Policy. This differs from
traditional VPN configuration where connections are configured manually or distributed
through the connection manager administration kit. Once you have added the computer�s client
account to the designated security group, you need to install a computer certificate on the client
for the purpose of DirectAccess authentication. An organization needs to deploy Active
Directory
Certificate Services so that clients can automatically enroll with the appropriate certificates.