You work as the enterprise exchange administrator at TestKing.com. TestKing.com makes use of Microsoft Exchange Server messaging solution. The TestKing.com network consists of a single ActiveDirectory forest that contains a single named testking.com. TestKing.com has its headquartets in Chicago and 15 branch offices around the globe， which are configured as Active Directory sites. The branch offices of Testking.com are connected to the Chicagooffices and directly to the Internet. For the future， all the branch offices should have Exchange Server 2010 Hub Transport server that hasfollowing characteristics： 1. The Internet connections of the branch offices should be used to send e-mail. 2. The e-mail messages from the branch offices to the Chicago offices should go via a WAN link. 3. The branch offices should not use the WAN link to send e-mail to via the Internet 4. Administrative overhead should be reduced. What should you do？（）

A. The best option is to use 10 Send connectors at every office.
B. The best option is to use one SMTP site link at every office.
C. The best option is to use one Send connector at every office.
D. The best option is to use two Send connectors at every office.