You work as the enterprise exchange administrator at Company.com.The Company.com network consists of a single Active Directory domain named Company.com.Company.com has an Exchange Server 2010 organization.the Company.com contains two exchange server 2010 client access server named -ex14 and - ex15 that has imap4 installed.remote users from the internet make use of imap4 to connect to -ex14 and -ex15.you have received instructions from the cio not to allow the users to use imap4 to connect to their mailboxes on -ex15. What should you do？（）

A. the best option is to change the imap4 retrieval settings on -ex15.
B. the best option is to access the -ex15 and disable the imap4 mailbox feature for the mailboxes.
C. the best option is to configure the windows firewall on -ex14 to block tcp port 25 and 110.
D. the best option is to configure the windows firewall on -ex14 to block tcp port 110 and 995.