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 domain named testking.com. TestKing.com has its headquarters in Chicago and a branch office in Dallas. Both offices are an ActiveDirectory site that is connected to each other via WAN link. You receive an intruction from management toplan the installation of Exchange Server 2010 in both offices. You need to ensure that user access ismaintained in the event of a server failure as well as keepin the amount of Exchange servers in bothActive Directory sites to a minimum. What should you do？（）

A. The best option is to install four servers in every Active Directory site.
B. The best option is to install three servers in every Active Directory site.
C. The best option is to install two servers in every Active Directory site.
D. The best option is to install one servers in every Active Directory site.