问题：

[单选]

You are attending a meeting on Microsoft Windows Meeting Space. At the same time， you attempt to join a second meeting also hosted on Windows Meeting space. The dialog box that allows you to join the second meeting fails to open. You need to join the second meeting. 
What should you do？（）

A . Join the second meeting by using Microsoft Office Live Meeting.
B . Enable the Windows Media Player Network Sharing Service Windows Firewall exception.
C . Click the Leave meeting option in the first meeting， and then join the second meeting. 
D . Open Windows Meeting Space， create a new meeting， and specify a password for others to use when they join the meeting.