You have an Active Directory forest that contains a single site.Your organization contains the Exchange Server 2010 servers shown in the following table： All clients connect from the Internet by using IMAP4.You need to prevent some users from using IMAP4 to connect to the mailboxes Server5. What should you do？（）

• A、Modify the IMAP4 retrieval settings on Server5.
• B、Disable the IMAP4 mailbox feature for the mailboxes on Server5.
• C、On Server5， configure Windows Firewall to block TCP port 25 and TCP port 110.
• D、On Server5， configure Windows Firewall to block TCP port 110 and TCP port 995.