Your company has a Microsoft Hyper-V Server 2008 R2 environment. You manage the environment by using Microsoft System Center Virtual Machine Manager （VMM） 2008 R2. You attempt to migrate child partitions through a firewall by using network migration. The migration fails. You need to ensure that you can successfully complete the migration. Which firewall port should you open？（）

• A、80
• B、135
• C、445
• D、8554