问题：

[单选] You work as a network Exchange administrator at Company.com.The Company.com network currently consists of a single Active Directory forest containing a single domain named Company.com.The Company.com organization makes use of Microsoft Exchange Server 2010 as their messaging solution.you are responsible for managing two edge transport servers named -ex05 and -ex06.to ensure productivity within the organization you receive an instruction to make sure that e-mail messages sent from the internet is sent to -ex06 in the event of -ex05 failing. What should you do？（）

A . This can be accomplished by creating two MX records.Then the mx record for -ex05 should be assigned a priority of 20.Thereafter the mx record for -ex06 should be assigned a priority of 10.
B . This can be accomplished by creating two SRV records.Then the srv record for -ex05 should be assigned a priority of 20.Thereafter the srv record for -ex06 should be assigned a priority of 10.
C . This can be accomplished by creating two MX records.Then the mx record for -ex05 should be assigned a priority of 10.Thereafter the mx record for -ex06 should be assigned a priority of 20.
D . This can be accomplished by creating two SRV records.Then the srv record for -ex05 should be assigned a priority of 10.Thereafter the srv record for -ex06 should be assigned a priority of 20.