You have an Exchange Server 2010 SP1 organization that contains a CAS array. There are
two servers, named CAS-01 and CAS-02, in the CAS array.
You have a machine on the internal network called Test1. When one Client Access server
crashes Test1 cannot download the autodiscover details from the Client Access Server
array.
Which cmdlet should you use to rectify this?

A.
Set-ClientAccessArray.

B.
Set-ClientAccessServer.

C.
New-AutodiscoverVirtualDirectory.

D.
Set-AutodiscoverVirtualDirectory.

Explanation:
Make sure both CAS in the array have the correct autodiscover information: SetClientAccessServer -Identity
“CAS-01” -AutoDiscoverServiceInternalUri
“https://cas01.contoso.com/autodiscover/autodiscover.xml”

http://technet.microsoft.com/en-us/library/bb125157