You are a help desk technician for your company. A portion of your company’s network is shown in the exhibit. Michael is an employee in your company’s marketing department. Michael uses a Windows XP Professional computer that is located on Subnet A. You use a Windows XP Professional computer that is located on Subnet B. The company’s firewall does not use Network Address Translation (NAT). Michael sends you a Remote Assistance invitation. In Windows Messenger, you accept the invitation, but you cannot connect to Michael’s computer. Next, you run the Ping command, which verifies connectivity to Michael’s computer. You need to establish a Remote Assistance connection with Michael’s computer. What should you do next?（） 

• A、Ask your firewall administrator to open the TCP/IP ports that are used by Windows Messenger.
• B、Ask your firewall administrator to open the TCP/IP ports that are used by Remote Desktop Services. 
• C、Instruct Michael to create an invitation file and then e-mail the file to you as a file attachment. When you receive the e-mail, open the file attachment. 
• D、Instruct Michael to edit the System properties for his computer and add your domain user account to the Remote Desktop Users list on the Remote tab.