You have an Exchange Server 2010 organization. The organization is authoritative for the domain contoso.com.

You create a federated trust.

You need to ensure that federated partners can automatically locate the Client Access servers in the organization.

What should you create from an external DNS server?

A.
an A record for autodiscover.contoso.com.

B.
an A record for FederatedSharing.contoso.com.

C.
an SRV record for _autodiscover._TCP._msdcs.contoso.com.

D.
an SRV record for _FederatedSharing._UDP._msdcs.contoso.com.

Explanation:
As mentioned in another question, this should actually be a CNAME record, according to Technet, but I left this in here as an A record for contoso.com would need creating before the CNAME for autodiscover.contoso.com. The exam will only mention CNAME records though.

Reference:

http://technet.microsoft.com/en-us/library/ff601760.aspx