You need to modify the Exchange-specific cost for a site link named Link1

You need to modify the Exchange-specific cost for a site link named Link1.
What should you do?

A.
From the Exchange Management Shell, run the Set-ADSite cmdlet.

B.
From the Exchange Management Shell, run the Set-ADSiteLink cmdlet.

C.
From the Active Directory Sites and Services snap-in, create a site link bridge.

D.
From the Active Directory Sites and Services snap-in, modify the properties of Link1.

Explanation:
Set-AdSiteLink -Identity Link1 -ExchangeCost 10
http://technet.microsoft.com/en-us/library/bb266946.aspx