You are the Exchange administrator for your company. The company’s network consists of a single Active Directory forest.
The forest contains three domains named Domain1, Domain2, and Domain3. The functional level of the domains is Windows 2000 mixed.
Domain1 contains a single Exchange 2000 Server computer named Exch1. Domain2 contains a single Exchange 2000 Server computer named Exch2.
Domain3 contains a single Exchange Server 5.5 computer named Exch3, which runs Windows 2000 Server.
Exchange 2000 Server Active Directory Connector (ADC) is installed on Exch1 and Exch2. There is a two-way connection agreement on Exch1.
This connection agreement replicates changes between Domain1 and Exch3. There is also a two-way connection agreement on Exch2. This connection agreement replicates changes between Domain2 and Exch3.
You upgrade ADC on Exch1 to Exchange server 2003 ADC. The connection agreement updates and replicates normally.
Then you notice that the connection agreements on Exch2 stop replicating.
You need to ensure that all connection agreements are replicating properly.
What are two possible ways to achieve this goal? (Each correct answer presents a complete solution. Choose two)

A.
Move all connection agreements from Exch2 to Exch1.

B.
Upgrade ADC on Exch2 to Exchange Server 2003 ADC.

C.
Promote Exch2 to a domain controller and a global catalog server.

D.
Raise the functional level on Domain3 to Windows 2000 native.

Explanation:
Because Exch1 is already working, we can achieve the solution by moving the
agreements from Exch2 to Exch1. Because of the different ADC versions are running,
they also need to upgrade ADC in the Exch2 domain.
Reference
Exchange 2003 Administration guide